Hazardous waste management (Buxus papillosa) investment for the prosperity of environment and circular economy: Response surface methodology-based simulation.

Dealing with the current defaults of environmental toxicity, heating, waste management, and economic crises, exploration of novel non-edible, toxic, and waste feedstock for renewable biodiesel synthesis is the need of the hour. The present study is concerned with Buxus papillosa with seeds oil concentration (45% w/w), a promising biodiesel feedstock encountering environmental defaults and waste management; in addition, this research performed simulation based-response surface methodology (RSM) for Buxus papillosa bio-diesel. Synthesis and application of novel Phyto-nanocatalyst bimetallic oxide with Buxus papillosa fruit capsule aqueous extract was advantageous during transesterification. Characterization of sodium/potassium oxide Phyto-nanocatalyst confirmed 23.5 nm nano-size and enhanced catalytic activity. Other characterizing tools are FTIR, DRS, XRD, Zeta potential, SEM, and EDX. Methyl ester formation was authenticated by FTIR, GC-MS, and NMR. A maximum 97% yield was obtained at optimized conditions i.e., methanol ratio to oil (8:1), catalyst amount (0.37 wt%), reaction duration (180 min), and temperature of 80 °C. The reusability of novel sodium/potassium oxide was checked for six reactions. Buxus papillosa fuel properties were within the international restrictions of fuel. The sulphur content of 0.00090% signified the environmental remedial nature of Buxus papillosa methyl esters and it is a highly recommendable species for biodiesel production at large scale due to a t huge number of seeds production and vast distribution.

Revealing the mechanism of quartz sand seeding in accelerating phosphorus recovery from anaerobic fermentation supernatant through vivianite crystallization.

The recovery of phosphorus (P) through vivianite crystallization offers a promising approach for resource utilization in wastewater treatment plants. However, this process encounters challenges in terms of small product size and low purity. The study aimed to assess the feasibility of using quartz sand as a seed material to enhance P recovery and vivianite crystal characteristics from anaerobic fermentation supernatant. Various factors, including seed dosage, seed size, Fe/P ratio, and pH, were systematically tested in batch experiments to assess their influence. Results demonstrated that the effect of seed enhancement on vivianite crystallization was more pronounced under higher seed dosages, smaller seed sizes, and lower pH or Fe/P ratio. The addition of seeds increased P recovery by 4.43% in the actual anaerobic fermentation supernatant and also augmented the average particle size of the recovered product from 19.57 to 39.28 µm. Moreover, introducing quartz sand as a seed material effectively reduced co-precipitation, leading to a notable 12.5% increase in the purity of the recovered vivianite compared to the non-seeded process. The formation of an ion adsorption layer on the surface of quartz sand facilitated crystal attachment and growth, significantly accelerating the vivianite crystallization rate and enhancing P recovery. The economic analysis focused on chemical costs further affirmed the economic viability of using quartz sand as a seed material for P recovery through vivianite crystallization, which provides valuable insights for future research and engineering applications.

Phosphorus recovery from synthetic anaerobic fermentation supernatant via vivianite crystallization: Coupling effects of various physicochemical process parameters.

Recovery of phosphorus (P) via vivianite crystallization is an effective strategy to recycle resources from the anaerobic fermentation supernatant. However, the presence of different components in the anaerobic fermentation supernatant (e.g., polysaccharides and proteins) might alter conditions for optimal growth of vivianite crystals, resulting in distinct vivianite characteristics. In the present study, the effect of different components on vivianite crystallization was explored. Then, the reaction parameters (pH, Fe/P, and stirring speed) for P recovery from synthetic anaerobic fermentation supernatant as vivianite were optimized using response surface methodology, and the relationship between crystal properties and supersaturation was elucidated using a thermodynamic equilibrium model. The optimized values for pH, Fe/P, and stirring speed were found to be 7.8, 1.74, and 500 rpm respectively, resulting in 90.54 % P recovery efficiency. Moreover, the variation of reaction parameters did not change the crystalline structure of the recovered vivianite but influenced its morphology, size, and purity. Thermodynamic analysis suggested the saturation index (SI) of vivianite increased with increasing pH and Fe/P ratio, leading to a facilitative effect on vivianite crystallization. However, when the SI was >11, homogenous nucleation occurred so that the nucleation rate was much higher than the crystal growth rate, causing a smaller crystal size. The findings presented herein will be highly valued for the future large-scale application of the vivianite crystallization process for wastewater treatment.

Recovery of phosphorus from wastewater containing humic substances through vivianite crystallization: Interaction and mechanism analysis.

Vivianite crystallization has been regarded as a suitable option for recovering phosphorus (P) from P-containing wastewater. However, the presence of humic substances (HS) would inevitably affect the formation of vivianite crystals. Therefore, the influences of HS on vivianite crystallization and the changes in the harvested vivianite crystals were investigated in this study. The results suggested the inhibition effect of 70 mg/L HS on vivianite crystallization reached 12.24%, while it could be attenuated by increasing the pH and Fe/P ratio of the solution. Meanwhile, the addition of HS altered the size, purity, and morphology of recovered vivianite crystals due to the blockage of the growth sites on the crystal surface. Additionally, the formation of phosphate ester group, hydrogen bonding, and COOH-Fe2+ complexes are the potential mechanisms of HS interaction with vivianite crystals. The results obtained herein will help to elucidate the underlying mechanism of HS on vivianite crystallization from P-containing wastewater.

Flotation purification of waste high-silica phosphogypsum.

High-silica phosphogypsum (PG) is a kind of industrial by-product with great utilization potential. However, it is difficult to reuse PG directly due to the related gangue minerals (e.g., SiO2), and thus efficient purification is required to allow its further applications. Herein, a typical high-silica phosphogypsum waste was purified by a new "reverse-direct flotation" method. The organic matters and fine slimes were removed by reverse flotation, and then, the silica impurity was removed by direct flotation. Via the closed-circuit flotation process, the whiteness of the PG concentrate is improved from 33.23 to 63.42, and the purity of gypsum in the PG concentrate increases from 83.90% to 96.70%, with a gypsum recovery of 85%. Additionally, the content of SiO2 is significantly reduced from 11.11% to 0.07%. In-depth investigations suggest that the difference in the floatability of gypsum and quartz is prominently intensified by flotation reagents at pH = 2-2.5, and thus leads to good desilication performance. Further characteristics of the PG concentrate prove that impurities have been well removed, and the PG concentrate meets the requirement of related standards for gypsum building materials. The flotation method reported here paves the way for the purification of high-silica phosphogypsum, which can be extended to the purification and value-added reutilization of other industrial solid wastes.

Microplastics aging in wastewater treatment plants: Focusing on physicochemical characteristics changes and corresponding environmental risks.

Microplastics (MPs) have been frequently detected in effluent wastewater and sludge in wastewater treatment plants (WWTPs), the discharge and agricultural application of which represent a primary source of environmental MPs contamination. As important as quantitative removal is, changes of physicochemical characteristics of MPs (e.g., shapes, sizes, density, crystallinity) in WWTPs are crucial to their environmental behaviors and risks and have not been put enough attention yet. This review is therefore to provide a current overview on the changes of physicochemical characteristics of MPs in WWTPs and their corresponding environmental risks. The changes of physicochemical characteristics as well as the underlying mechanisms of MPs in different successional wastewater and sludge treatment stages that mainly driven by mechanical (e.g., mixing, pumping, filtering), chemical (e.g., flocculation, advanced oxidation, ultraviolet radiation, thermal hydrolysis, incineration and lime stabilization), biological (e.g., activated sludge process, anaerobic digestion, composition) and their combination effects were first recapitulated. Then, the inevitable correlations between physicochemical characteristics of MPs and their environmental behaviors (e.g., migration, adsorption) and risks (e.g., animals, plants, microbes), are comprehensively discussed with particular emphasis on the leaching of additives and physicochemical characteristics that affect the co-exist pollutants behavior of MPs in WWTPs on environmental risks. Finally, knowing the summarized above, some relating unanswered questions and concerns that need to be unveiled in the future are prospected. The physicochemical properties of MPs change after passing through WWTP, leading to subsequent changes in co-contaminant adsorption, migration, and toxicity. This could threaten our ecosystems and human health and must be worth investigating.

Enhanced methane production from anaerobic digestion of waste activated sludge through preliminary pretreatment using calcium hypochlorite.

Methane recovery from waste activated sludge (WAS) through anaerobic digestion is generally restricted by the poor degradability of WAS. Herein, a novel sludge pretreatment technology by using the calcium hypochlorite (Ca(ClO)2) in enhancing the methane production from WAS anaerobic digestion was reported. The solubilization of WAS was significantly increased after 10-240 mg Ca(ClO)2/g VS (VS: volatile solids) pretreatment for 48 h, under which the solubilization was 1.7-3.4 folds (i.e., 0.17-0.34 mg SCOD/mg VS; SCOD: soluble chemical oxygen demand) higher than that without Ca(ClO)2 pretreatment (i.e., 0.1 mg SCOD/mg VS). Correspondingly, the methane production was increased from 250.0 ± 5.3 mL/g VS to 385.1 ± 3.3 mL/g VS with the doses of Ca(ClO)2 increasing from 10 mg/g VS to 240 mg/g VS, resulted in an increasing methane production of 3.6%-59.7% than that without Ca(ClO)2 pretreatment. The microbial community composition results exhibited that the populations of key acidogens (e.g., Longilinea sp.) and methanogens (e.g., Methanosaeta sp.) were both reduced significantly. Moreover, Ca(ClO)2 decreased the cells viability, leading to a 76.2% reduction of living cells fraction. Accordingly, it was further confirmed that high dosage of Ca(ClO)2 could inhibit three microbial-related processes relevant to methane production, i.e., acidification, hydrolysis and methanogenesis.

Multifunctional YY1 in Liver Diseases.

The transcription factor Yin Yang 1 (YY1) is a multifunctional protein that can activate or repress gene expression, depending on the cellular context. While YY1 is ubiquitously expressed and highly conserved between species, its role varies among the diverse cell types and includes proliferation, differentiation, and apoptosis. Upregulated YY1 expression is found in pathogenic conditions, such as human hepatocellular carcinoma and hepatitis B virus infection, and its roles in the molecular pathogenic mechanisms in liver (i.e., fibrosis, carcinogenesis, viral-induced injury) are currently being elucidated. The most recent studies have revealed that YY1 is deeply involved in such dysregulated cellular metabolisms as glycometabolism, lipid metabolism, and bile acid metabolism, which are all involved in various diseases. In this review, we will summarize the current knowledge on YY1 in liver diseases, providing a focused discussion on the characterized and probable underlying mechanisms, as well as a reasoned evaluation of the potential for YY1-mediated pathology as drug targets in liver disease therapies.

Free nitrous acid-based nitrifying sludge treatment in a two-sludge system enhances nutrient removal from low-carbon wastewater.

A new method to enhance nutrient removal from low carbon-wastewater was developed. The method consists of a two-sludge system (i.e., an anaerobic-anoxic-oxic reactor coupled to a nitrifying reactor (N-SBR)) and a nitrifying-sludge treatment unit using free nitrous acid (FNA). Initially, 65.1±2.9% in total nitrogen removal and 69.6±3.4% in phosphate removal were obtained without nitrite accumulation. When 1/16 of the nitrifying sludge was daily treated with FNA at 1.1mgN/L for 24h, ∼28.5% of nitrite was accumulated in the N-SBR, and total nitrogen and phosphate removal increased to 72.4±3.2% and 76.7±2.9%, respectively. About 67.8% of nitrite was accumulated at 1.9mgN/L FNA, resulting in 82.9±3.8% in total nitrogen removal and 87.9±3.5% in phosphate removal. Fluorescence in-situ hybridization analysis showed that FNA treatment reduced the abundance of nitrite oxidizing bacteria (NOB), especially that of Nitrospira sp.

Unraveling microbial structure and diversity of activated sludge in a full-scale simultaneous nitrogen and phosphorus removal plant using metagenomic sequencing.

Activated sludge contains highly complex microbial communities, which play crucial roles in pollutant removal performance in wastewater treatment plants (WWTPs). Metagenomic sequencing was applied to characterize microbial community and functional profiles within activated sludge from a full-scale municipal WWTP carrying out simultaneous nitrogen and phosphorous removal (SNPR). We applied the assembled contigs (N90 of 591bp) and predicted genes to conduct taxonomic and function annotations, respectively. Results revealed the extraordinary microbial diversity of activated sludge, which included detection of minority populations that are difficult to be explored by traditional molecular methods. Taxonomic analysis indicated that the dominant bacterial phyla were Proteobacteria, Nitrospirae, Bacteroidetes, Actinobacteria and Firmicutes. The abundance of the key organisms involved in nitrogen and phosphorous removal were qualified. Aerobic ammonia-oxidizing bacteria distinctly dominate over ammonia-oxidizing archaea and anaerobic ammonium oxidation bacteria. Various key enzymes involved in the global nitrogen cycle were annotated in the activated sludge. High abundance of the known polyphosphate accumulating organisms was detected (approximately 4.89% of the overall population reads), supporting good phosphorous removal performance. This study provides a comprehensive insight into the community structure and diversity of the SNPR system, and will provide foundation for optimal operation of nutrient removal systems.

Mathematical Modeling of Nitrous Oxide Production during Denitrifying Phosphorus Removal Process.

A denitrifying phosphorus removal process undergoes frequent alternating anaerobic/anoxic conditions to achieve phosphate release and uptake, during which microbial internal storage polymers (e.g., Polyhydroxyalkanoate (PHA)) could be produced and consumed dynamically. The PHA turnovers play important roles in nitrous oxide (N2O) accumulation during the denitrifying phosphorus removal process. In this work, a mathematical model is developed to describe N2O dynamics and the key role of PHA consumption on N2O accumulation during the denitrifying phosphorus removal process for the first time. In this model, the four-step anoxic storage of polyphosphate and four-step anoxic growth on PHA using nitrate, nitrite, nitric oxide (NO), and N2O consecutively by denitrifying polyphosphate accumulating organisms (DPAOs) are taken into account for describing all potential N2O accumulation steps in the denitrifying phosphorus removal process. The developed model is successfully applied to reproduce experimental data on N2O production obtained from four independent denitrifying phosphorus removal study reports with different experimental conditions. The model satisfactorily describes the N2O accumulation, nitrogen reduction, phosphate release and uptake, and PHA dynamics for all systems, suggesting the validity and applicability of the model. The results indicated a substantial role of PHA consumption in N2O accumulation due to the relatively low N2O reduction rate by using PHA during denitrifying phosphorus removal.

Yin-Yang Regulation of RORγt Protein Complex in Th17 Differentiation.

T helper 17 (Th17) cells have been identified as a distinct T helper lineage that mediates tissue inflammation. Retinoic acid receptor-related orphan receptor (ROR) γt has been identified as the master transcription factor (TF) required for Th17 cell lineage commitment. There is an established consensus that TFs never function alone. Thus, RORγt is considered to form protein complexes that mediate Th17 cell differentiation. Given the importance of RORγt complexes in Th17 cell development and function, here, we summarize recent progress in research investigating the interaction of RORγt with potential partners, highlighting detailed mechanisms that direct Th17 cell differentiation and potential therapeutic targets in inflammatory diseases.

Oral immunization with rotavirus VP7 expressed in transgenic potatoes induced high titers of mucosal neutralizing IgA.

Rotaviruses (RV) are a common cause of severe diarrhea in young children, resulting in nearly one million deaths worldwide annually. Rotavirus VP7 was the rotavirus neutralizing protein. Previous study reported that VP7 DNA vaccine can induce high levels of IgG in mice but cannot protect mice against challenge (Choi, A.H., Basu, M., Rae, M.N., McNeal, M.M., Ward, R.L., 1998. Virology 250, 230-240). We found that rotavirus VP7 could maintain its neutralizing immunity when it was transformed into the potato genome. Mice immunized with the transformed tubers successfully elicited serum IgG and mucosal IgA specific for VP7. The mucosal IgA titer was as high as 1000, while serum IgG titer was only 600. Neutralizing assays indicated that IgA could neutralize rotavirus. These results indicate the potential usefulness of plants for production and delivery of edible rotavirus vaccines.