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We propose a novel, to our knowledge, step-adaptive cross-correlation algorithm tailored for distributed acoustic sensing systems based on linear frequency modulation pulses, aiming for rapid demodulation. This algorithm adjusts its step length through an adaptive "successive refinement" search strategy, which greatly improves computational efficiency by reducing the number of cross-correlation computations. Experimental results have shown that the demodulation time can be reduced by approximately 15 times compared to the conventional method, while maintaining the same demodulation result.
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Food waste anaerobic digestate (FWAD) containing high concentrations of contaminants must be purified or recycled. Bio-conditioning dewatering followed by activated sludge process (BDAS) has emerged as a promising technology for treating FWAD. However, the bio-conditioning dewatering as a pivotal step of BDAS is often negatively affected by low ambient temperatures often occurred in winter. This study investigated the role of heating FWAD in improving the bio-conditioning dewatering performance of FWAD. Batch experiments demonstrated that the bio-conditioning dewatering efficiency increased with temperature rise. Notably, due to the low energy consumption, 50°C was considered to be the most appropriate heating treatment temperature, realizing a drastic reduction of specific resistance to filtration (SRF) of bio-conditioned FWAD from initial 1.24 × 1012â m/kg in the control at a ambient temperature of 10°C to 5.42 × 1011â m/kg and a saving of 25% in bio-conditioning reagents cost. The results of the pilot-scale and large-scale experiments revealed that heating treatment made the bio-conditioning dewatering more stable regardless of the fluctuation of ambient temperature in practical engineering. The decrease in the viscosity of bio-conditioned FWAD and the enhancement in microbial fermentation liquor flocculation capacity through heating treatment played pivotal roles in improving the bio-conditioning dewatering performance of FWAD. This work provides a cost-effective strategy to achieve efficient bio-conditioning dewatering at a relatively low ambient temperature, which was helpful in the engineering application of the novel BDAS process in wastewater treatment.
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The activated sludge process is the most widely used technology for treating municipal wastewater. However, thick foam often occurs in activated sludge process. Here, we reported for the first time the effect of food waste hydrolysate (FWH) as an external carbon source on defoaming in activated sludge process. The study found that FWH was effective in defoaming at a wide dose range of 50-1600 mg/L total solids, as exhibiting that the foaming tendency of FWH-added foam mixed liquor was reduced to 0 mL-foam/mL-air·min from initial 0.171 mL-foam/mL-air·min in the control without adding FWH with 100 % of defoaming efficiency. Fatty acids, oils, and solid particles in FWH jointly contributed to the deformation. Among these factors, the concentration of long-chain unsaturated fatty acids was mainly responsible for the defoaming. This work provides a cost-effective strategy to solve the foaming problem in activated sludge process as well as providing external carbon sources.
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Carbono , Aguas del Alcantarillado , Aguas Residuales , Aguas del Alcantarillado/química , Carbono/química , Aguas Residuales/química , Hidrólisis , Purificación del Agua/métodos , Alimentos , Eliminación de Residuos Líquidos/métodos , Residuos , Ácidos Grasos , Alimento Perdido y DesperdiciadoRESUMEN
Simultaneously stabilizing of arsenic (As) and cadmium (Cd) in co-contaminated soil presents substantial challenges due to their contrasting chemical properties. Schwertmannite (Sch) is recognized as a potent adsorbent for As pollution, with alkali modification showing promising results in the simultaneous immobilization of both As and Cd. This study systematically investigated the long-term stabilization efficacy of alkali-modified Sch in Cd-As co-contaminated farmland soil over a 200-day flooding-drying period. The results revealed that As showed significant mobility in flooded conditions, whereas Cd exhibited increased soil availability under drying phases. The addition of Sch did not affect the trends in soil pH and Eh fluctuations; nonetheless, it led to an augmentation in the levels of amorphous iron oxides and SO42- concentration in soil pore water. At a dosage of 0.5% Sch, there was a notable decrease in the mobility and soil availability of As and Cd under both flooding (34.5% and 53.6% at Day 50) and drying conditions (27.0% and 29.4% at Day 130), primarily promoting the transformation of labile metal(loid) fraction into amorphous iron oxide-bound forms. Throughout the flooding-drying treatment period, Sch maintained stable mineral morphology and mineralogical phase, highlighting its long-term stabilization effect. The findings of this study emphasize the promising application of Sch-based soil remediation agents in mitigating the challenges arising from As-Cd co-contamination. Further research is warranted to explore their application in real farmland settings and their impact on the uptake of toxic metal(loid)s by plants.
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Arsénico , Cadmio , Restauración y Remediación Ambiental , Inundaciones , Contaminantes del Suelo , Suelo , Arsénico/análisis , Cadmio/análisis , Suelo/química , Restauración y Remediación Ambiental/métodos , Compuestos de Hierro/química , Granjas , AdsorciónRESUMEN
Lactic acid-rich fermentation liquid (LAFL) of food waste is found to act as a promising alternative carbon source for nitrogen removal in wastewater treatment. Here, LAFL was employed to investigate its impacts on nitrogen removal during raw municipal wastewater treatment with a comparison to sodium acetate (NaAc). Results indicated that nitrogen removals were comparable when incorporated with LAFL and NaAc (92.89 % v.s. 91.23 %). Unlike the utilization of NaAc, using LAFL could avoid suppressing the relative abundance of the nitrification genes and thus pose a negative risk to nitrogen removal during prolonged operation. The introduction of LAFL increased the stability and robustness of the functional microbial community and effectively reduced excess activated sludge (AS) generation by 109 % compared to NaAc addition, consequently enhancing nitrogen removal but diminishing the treatment cost. In general, LAFL exhibits prospective engineering application potentials and economic advantages in improving nitrogen removal by AS process.
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Eliminación de Residuos , Purificación del Agua , Fermentación , Aguas Residuales , Eliminación de Residuos Líquidos/métodos , Alimento Perdido y Desperdiciado , Reactores Biológicos , Desnitrificación , Alimentos , Nitrógeno , Carbono , Estudios Prospectivos , Aguas del Alcantarillado , Ácido LácticoRESUMEN
Bio-conditioning dewatering followed by activated sludge process (BDAS) is a promising technology for purifying food waste anaerobic digestate (FWAD). However, the bio-conditioning dewatering efficiency is often affected by FWAD properties and ambient temperature. Here, we firstly reported that aeration pre-treatment of FWAD played an important role in improving the bio-conditioning dewatering performance of FWAD. The study found that the accumulated carbonate (CO32-) in FWAD severely affected the flocculation of Fe-containing flocculant formed in microbial fermentation liquor due to the competitive consumption of the flocculant by CO32-. The capillary suction time (CST) and specific resistance to filtration (SRF) of the bio-conditioned FWAD increased from initial 77.8 s and 2.0 × 1012 m/kg to 122.7 s and 3.4 × 1012 m/kg, respectively, within 1 day of aeration. Prolonged aeration pre-treatment of FWAD could reduce its CO32- concentration and total alkalinity. Additionally, the aeration pre-treatment simultaneously decreased the proportion of macromolecular organic matter that hindered dewatering and the content of total solids (TS) and hydrophilic protein-like substances in FWAD. After 20 days of aeration followed by bio-conditioning, the CST and SRF reduced to final 36.5 s and 2.3 × 1011 m/kg, respectively, indicating a substantial improvement in dewatering performance. Successive forced aeration combined with the addition of CaCl2 to eliminate adverse factors mainly CO32- was a feasible and cost-effective strategy to realize bio-conditioning dewatering of FWAD in less than 2 days and a lower reagents dose of bio-conditioning, which was helpful in the engineering application of the novel BDAS process for FWAD purification.
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Alimentos , Eliminación de Residuos , Anaerobiosis , Alimento Perdido y Desperdiciado , FermentaciónRESUMEN
Colorful circularly polarized luminescence materials are desired for 3D displays, information security and asymmetric synthesis, in which single-emitted materials are ideal owing to self-absorption avoidance, evenly entire-visible-spectrum-covered photon emission and facile device fabrication. However, restricted by the synthesis of chiral broad-luminescent emitters, the realization and application of high-performing single-emitted full-color circularly polarized luminescence is in its infancy. Here, we disclose a single-emitted full-color circularly polarized luminescence system (spiral full-color emission generator), composed of whole-vis-spectrum emissive quantum dots and chiral liquid crystals. The system achieves a maximum luminescence dissymmetry factor of 0.8 and remains an order of 10-1 in visible region by tuning its photonic bandgap. We then expand it to a series of desired customized-color circularly polarized luminescence, build chiral devices and further demonstrate the working scenario in the photoinduced enantioselective polymerization. This work contributes to the design and synthesis of efficient chiroptical materials, device fabrication and photoinduced asymmetric synthesis.
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As a superior alternative to sutures, tissue adhesives have been developed significantly in recent years. However, existing tissue adhesives struggle to form fast and stable adhesion between tissue interfaces, bond weakly in wet environments and lack bioactivity. In this study, a degradable and bioactive citrate-based polyurethane adhesive is constructed to achieve rapid and strong tissue adhesion. The hydrophobic layer was created with polycaprolactone to overcome the bonding failure between tissue and adhesion layer in wet environments, which can effectively improve the wet bonding strength. This citrate-based polyurethane adhesive provides rapid, non-invasive, liquid-tight and seamless closure of skin incisions, overcoming the limitations of sutures and commercial tissue adhesives. In addition, it exhibits biocompatibility, biodegradability and hemostatic properties. The degradation product citrate could promote the process of angiogenesis and accelerate wound healing. This study provides a novel approach to the development of a fast-adhering wet tissue adhesive and provides a valuable contribution to the development of polyurethane-based tissue adhesives.
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Endowing three-dimensional (3D) displays with flexibility drives innovation in the next-generation wearable and smart electronic technology. Printing circularly polarized luminescence (CPL) materials on stretchable panels gives the chance to build desired flexible stereoscopic displays: CPL provides unusual optical rotation characteristics to achieve the considerable contrast ratio and wide viewing angle. However, the lack of printable, intense circularly polarized optical materials suitable for flexible processing hinders the implementation of flexible 3D devices. Here, we report a controllable and macroscopic production of printable CPL-active photonic paints using a designed confining helical co-assembly strategy, achieving a maximum luminescence dissymmetry factor (glum) value of 1.6. We print customized graphics and meter-long luminous coatings with these paints on a range of substates such as polypropylene, cotton fabric, and polyester fabric. We then demonstrate a flexible textile 3D display panel with two printed sets of pixel arrays based on the orthogonal CPL emission, which lays an efficient framework for future intelligent displays and clothing.
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The time delay signature (TDS) of chaos generated in three schemes of optical injection has been investigated, and the mechanism of TDS suppression (TDSS) is revealed. The first scheme is a continuous-wave (CW) laser unidirectionally injecting into a chaotic laser, and the TDS of the chaotic laser is suppressed below 0.08 in this structure. The second scheme is a chaotic laser unidirectionally injecting into a CW laser, where the parameter range of TDSS lower than 0.06 of this structure is the largest among the three schemes. The third scheme is two CW lasers coupling to each other, and two chaotic lasers with TDS (T D S<0.1) suppression can be obtained simultaneously. For the further analysis of the mechanism of TDSS, the quasi-linear relationship between the synchronization coefficient and TDS is revealed. This study will provide insight into the generation of chaotic lasers by optical injection and promote the application of chaotic lasers.
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The physics principle of pulse flight positioning is the main theoretical bottleneck that restricts the spatial resolution of the existing Raman distributed optical fiber sensing scheme. Owing to the pulse width of tens of nanoseconds, the spatial resolution of the existing Raman distributed optical fiber sensing scheme with kilometer-level sensing distance is limited to the meter level, which seriously restricts the development of the optical time-domain reflection system. In this paper, a chaos laser is proposed in the context of the physical principle of the Raman scattering effect, and a novel theory of chaos Raman distributed optical fiber sensing scheme is presented. The scheme reveals the characteristics of chaos Raman scattering light excited by a chaotic signal on the sensing fiber. Further, the chaos time-domain compression demodulation mechanism between the temperature variation information and chaos correlation peak is demonstrated. Then, the position of the temperature variation signal is precisely located using the delay time of the chaos correlation peak combined with the chaos pulse flight time. Based on this novel optical sensing mechanism, an experiment with 10 cm spatial resolution and 1.4 km sensing distance was conducted, and the spatial resolution was found to be independent of the sensing distance. Within the limit of the existing spatial resolution theory, the spatial resolution of the proposed scheme is 50 times higher than that of the traditional scheme. The scheme also provides a new research direction for optical chaos and optical fiber sensing.
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This paper presents a scale factor calibration method based on virtual accelerations generated by electrostatic force. This method uses a series of voltage signals to simulate the inertial forces caused by the acceleration input, rather than frequent and laborious calibrations with high-precision instruments. The error transfer model of this method is systematically analyzed, and the geometrical parameters of this novel micromachined resonant accelerometer (MRA) are optimized. The experimental results demonstrate that, referring to the traditional earth's gravitational field tumble calibration method, the error of the scale factor calibration is 0.46% within ±1 g by using our method. Moreover, the scale factor is compensated by virtual accelerations. After compensation, the maximum temperature drift of the scale factor decreases from 2.46 Hz/g to 1.02 Hz/g, with a temperature range from 40 °C to 80 °C.
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Aromatic volatile organic compounds (VOCs) are a type of common pollution form in chemical contaminated sites. In this study, seven aromatic VOCs such as benzene, toluene, ethylbenzene, chlorobenzene, m-xylene, p-chlorotoluene and p-chlorotrifluorotoluene were used as the only carbon source, and four strains of highly efficient degrading bacteria were screened from the soil of chemical contaminated sites, then the synthetic bacterial consortium was constructed after mixing with an existing functional strain (Bacillus benzoevorans) preserved in the laboratory. After that, the synthetic bacterial consortium was used to explore the degradation effect of simulated aromatic VOCs polluted wastewater. The results showed that the functional bacterium could metabolize with aromatic VOCs as the only carbon source and energy. Meanwhile, the growth of the synthetic bacterial consortium increased with the additional carbon resources and the alternative of organic nitrogen source. Ultimately, the applicability of the synthetic bacterial consortium in organic contaminated sites was explored through the study of broad-spectrum activity.
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Compuestos Orgánicos Volátiles , Compuestos Orgánicos Volátiles/metabolismo , Biodegradación Ambiental , Tolueno/metabolismo , Benceno/metabolismo , Bacterias/metabolismo , Carbono/metabolismoRESUMEN
The increased demand for rare earth resources has led to an increase in the development of rare earth mines (REMs). However, the production of high-concentration leaching agents (SO4 2-) and heavy metals as a result of rare earth mining has increased, necessitating the removal of contaminants. Here, a series of experiments with different remediation measures, including control (CK), sulfate-reducing bacteria (SRB) alone (M), chemicals (Ca(OH)2, 1.5 g/kg) plus SRB (CM-L), chemicals (Ca(OH)2, 3.0 g/kg) plus SRB (CM-M), and chemicals (Ca(OH)2, 4.5 g/kg) plus SRB (CM-H), were conducted to investigate the removal effect of SO4 2-, Pb, Zn, and Mn from the REM soil. Then, a high-throughput sequencing technology was applied to explore the response of bacterial community diversity and functions with different remediation measures. The results indicated that CM-M treatment had a more efficient removal effect for SO4 2-, Pb, Zn, and Mn than the others, up to 94.6, 88.3, 98.7, and 91%, respectively. Soil bacterial abundance and diversity were significantly affected by treatments with the inoculation of SRB in comparison with CK. The relative abundance of Desulfobacterota with the ability to transform SO4 2- into S2- increased significantly in all treatments, except for CK. There was a strong correlation between environmental factors (pH, Eh, SO4 2-, Pb, and Zn) and bacterial community structure. Furthermore, functional prediction analysis revealed that the SRB inoculation treatments significantly increased the abundance of sulfate respiration, sulfite respiration, and nitrogen fixation, while decreasing the abundance of manganese oxidation, dark hydrogen oxidation, and denitrification. This provides good evidence for us to understand the difference in removal efficiency, bacterial community structure, and function by different remediation measures that help select a more efficient and sustainable method to remediate contaminants in the REM soil.
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Nations, industries, and aspects of everyday life have undergone forgery and counterfeiting ever since the emergence of commercialization. Securing documents and products with anticounterfeit additives shows promise for authentication, allowing one to combat ever-increasing global counterfeiting. One most-used effective encryption strategy is to combine with optical-security markers on the required protection objects; however, state-of-the-art labels still suffer from imitation due to their poor complexity and easy forecasting, as a result of deterministic production. Developing advanced anticounterfeiting tags with unusual optical characters and further incorporating complex security features are desired to achieve multimodal, unbreakable authentication capacity; unfortunately, this has not yet been achieved. Here, we prepare a series of stable circularly polarized luminescence (CPL) materials, composed of toxicity-free, high-quality-emitting inorganic quantum dots (QDs) and liquid crystals, using a designed helical-coassembly strategy. This CPL system achieves a figure of merit (FM, assessing the performance of both luminescence dissymmetry and quantum yield) value of 0.39, fulfilling practical demands for anticounterfeiting applications. Based on these CPL structures, we produce a type of multimodal-responsive security materials (MRSMs) that exhibits six different stimuli-responsive modes, including light activation, polarization, temperature, voltage, pressure, and view angle. Thus, we show a proof-of-principle blockchain-like integrated anticounterfeiting system, allowing multimodal-responsive, interactive/changeable information encryption-decryption. We further encapsulate the obtained security materials into a fiber to expand our materials to work on flexible fabrics, that is, building an intelligent textile with a color-adaptable function along with environmental change.
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Fungal mash derived from Aspergillus spp. is a green enzymatic additive for food waste (FW) valorization. In this study, the production of volatile fatty acids (VFAs) and the proportion of propionic acid (PA) in VFAs were increased by utilizing a complex enzyme (CE) obtained from Aspergillus oryzae. Results showed that CE addition significantly promoted SCOD concentration in the hydrolysis at a wide pH range from 4 to 9. In contrast, the production of VFAs was influenced by pH, and the highest yields of VFAs and PA were found at pH 7. At the CE dosage of 0.2 g/g VSS, the concentration of VFAs in the FW fermentation liquid reached 38.1 g COD/L with the PA proportion up to 42.7%, which increased by 107.9% and 63.7%, respectively, relative to that in the zero-dosage group. With CE continuing to be added, the C/N ratio declined, and the primary metabolic pathway was converted from acetic acid-type to PA-type. Further investigation of the dominant microbial communities and their metabolic capacities showed that the acrylate-mediated pathway was the potential metabolic reaction in PA-type fermentation. These results indicated that CE pretreatment was a feasible strategy to enhance the PA-rich fermentation of FW under neutral pH conditions.
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Alimentos , Eliminación de Residuos , Fermentación , Propionatos , Ácidos Grasos Volátiles , Ácidos , Concentración de Iones de Hidrógeno , Aguas del Alcantarillado , Reactores Biológicos/microbiología , AnaerobiosisRESUMEN
In our previous study, anaerobic digestion of food waste could be effectively enhanced by adding sulfidated nanoscale zero-valent iron (S-nZVI) under high-strength ammonia concentrations. In this study, in order to further elucidate the specific interactive effects of S-nZVI and ammonia on anaerobic digestion of nitrogen-rich food waste, the methanogenic performance of anaerobic digestion systems respectively added with nanoscale zero-valent iron (nZVI) and S-nZVI were compared and monitored under different ammonia stress conditions. Both nZVI and S-nZVI could effectively stimulate the methanogenesis process among ammonia concentrations ranging from 0 to 3500 mg/L. However, the enhancing effects of S-nZVI and nZVI on anaerobic digestion of food waste were different, in which anaerobic digestion systems added with S-nZVI and nZVI performed best under 2500 mg/L of ammonia and 1500 mg/L of ammonia, respectively. Furthermore, the analysis of microbial communities suggested that ammonia stress enriched acetoclastic methanogens, while adding nZVI and S-nZVI into anaerobic digestions stimulated the process of hydrogenotrophic methanogenesis. Moreover, S-nZVI performed better in promoting the evolution of DIET-related microorganisms than nZVI, resulting in enhanced methane production under high ammonia-stressed conditions. This work provided fundamental knowledge about the interactive effects of S-nZVI and ammonia on the anaerobic digestion of food waste.
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Eliminación de Residuos , Aguas del Alcantarillado , Anaerobiosis , Amoníaco , Hierro , Alimentos , MetanoRESUMEN
We demonstrate a broadband and wavelength-tunable chaotic laser by using a monolithically integrated wavelength-tunable chaotic semiconductor laser subject to optical feedback. The chip consists of a gain section, a distributed Bragg reflection grating section, a semiconductor optical amplifier section, and a phase section. By applying an optical feedback loop to the chaotic semiconductor laser chip, a nonlinear frequency mixing is stimulated in the laser cavity, and the chaos bandwidth is expanded to 33.6 GHz, which is 4.4 times larger than the bandwidth without optical feedback. Furthermore, the effect of feedback optical power on the bandwidth is investigated. The results show that the wide power spectrum of chaotic laser is available in a large wavelength range from 1556.44 nm to 1566.42 nm. This work explores a broadband and wavelength-tunable chaotic semiconductor laser for the wavelength division multiplexing to enlarge the capacity in chaotic secure optical communications.
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Reaction kinetics in biodegradation process is the basis and key of bioremediation technology, which can be used to predict the interaction between microorganisms and environmental states in the system. In this study, the kinetic model (Monod, Moser, Tessier and Cotonis) and kinetic parameters of aerobic biodegradation of functional bacteria in simulated wastewater polluted by aromatic volatile organic compounds (VOCs) were determined by shaking flask experiment. Monod, Moser, Tessier and Contois models were used to fit the experimental data and determine the kinetic parameters based on nonlinear regression analysis. Experimental results demonstrated that the removal rate of aromatic VOCs at 72 h was between 34.78 and 99.75% depending on the initial concentration of aromatic VOCs. The specific growth rate µ and degradation rate q increased with the increase of substrate concentration. The model of Monod, Moser and Tessier could be used to simulate microbial growth and substrate degradation in simulated aromatic VOCs polluted wastewater. Then the model and corresponding kinetic parameters were used to predict the limit concentration of biodegradation and provide theoretical support for the subsequent dynamic simulation and field engineering.
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Compuestos Orgánicos Volátiles , Aguas Residuales , Cinética , Compuestos Orgánicos Volátiles/metabolismo , Biodegradación Ambiental , Bacterias/metabolismoRESUMEN
We proposed a method based on the Brillouin optical time domain analysis (BOTDA) system to demodulate the length changes of the heating region using the intensity of probe light, under the premise that the temperature in the heating region does not change and the Brillouin frequency shift (BFS) of the heating region is known. This method can realize the recognition of small length under the condition of wide pulse width. The theoretical analysis shows that the different lengths of the heating region will lead to different gains when the spatial resolution corresponding to the pulse width of the pulsed light is larger than the length of the heating region. And through theoretical derivation and simulation, it is concluded that the relationship between the intensity of probe light and the length of the heating region satisfies the exponential growth. Further experiments verify that the exponential growth is approximately linear in the range of small length changes. The length of the heating region can be inversely deduced by using the linear relationship by detecting the intensity of probe light. When the length of sensing fiber is 100 m and the heating region changes from 2 cm to 8 cm, 1 cm heating region changes can be identified.