RESUMO
The electro-Fenton (EF) based on gas-diffusion electrodes (GDEs) reveals promising application prospective towards recalcitrant organics degradation because such GDEs often yields superior H2O2 generation efficiency and selectivity. However, the low efficiency of Fe2+/Fe3+ cycle with GDEs is always considered to be the limiting step for the EF process. In this study, activated carbon fiber (ACF) was firstly employed as co-catalyst to facilitate the performance of antibiotic cefaclor (CEC) decomposition in EF process. It was found that the addition of ACF co-catalyst achieved a rapid Fe2+/Fe3+ cycling, which significantly enhanced Fenton's reaction and hydroxyl radicals (â¢OH) generation. X-ray photoelectron spectroscopy (XPS) results indicated that the functional groups on ACF surface are related to the conversion of Fe3+ into Fe2+. Moreover, DMSO probing experiment confirmed the enhanced â¢OH production in EF + ACF system compared to conventional EF system. When inactive BDD and Ti4O7/Ti anodes were paired to EF system, the addition of ACF could significantly improve mineralization degree. However, a large amount of toxic byproducts, including chlorate (ClO3-) and perchlorate (ClO4-), were generated in these EF processes, especially for BDD anode, due to their robust oxidation capacity. Higher mineralization efficiency and less toxic ClO4- generation were obtained in the EF + ACF process with Ti4O7/Ti anode. This presents a novel alternative for efficient chloride-containing organic removal during wastewater remediation.
Assuntos
Antibacterianos , Fibra de Carbono , Cefaclor , Eletrodos , Peróxido de Hidrogênio , Ferro , Poluentes Químicos da Água , Fibra de Carbono/química , Antibacterianos/química , Peróxido de Hidrogênio/química , Poluentes Químicos da Água/química , Ferro/química , Cefaclor/química , Catálise , Carvão Vegetal/química , Técnicas Eletroquímicas/métodosRESUMO
The widespread existence of antibiotics in the environment has attracted growing concerns regarding the potential adverse effects on aquatic organisms, ecosystems, and human health even at low concentrations. Extensive efforts have been devoted to developing new methods for effective elimination of antibiotics from wastewater. Herein, a novel process of Fe2+ catalytically enhanced vacuum ultraviolet (VUV) irradiation was proposed as a promising approach for the removal of antibiotic trimethoprim (TMP) in water. Compared with UVC photolysis, VUV photolysis, and UVC/Fe2+, VUV/Fe2+ could increase the pseudo-first-order reaction rate constant of TMP removal by 6.6-38.4 times and the mineralization rate by 36.5%-59.9%. The excellent performance might originate from the synergistic effect of VUV and Fe2+, i.e., VUV irradiation could effectively split water and largely accelerate the Fe3+/Fe2+ cycle to generate more reactive oxygen species (ROS). EPR results indicated that â¢OH and O2â¢- were identified as the main ROS in the UVC/Fe2+ and VUV/Fe2+ processes, while â¢OH, O2â¢-, and 1O2 were involved in the VUV process. The operating parameters, such as Fe2+ dosage and initial TMP contents, were evaluated and optimized. Up to 8 aromatic intermediates derived from hydroxylation, demethylation, carbonylation, and methylene group cleavage were identified by UPLC-QTOF-MS/MS technique, the possible pathways of TMP degradation were proposed. Finally, the acute and chronic toxicity of intermediates formed during TMP degradation in the VUV/Fe2+ process were also evaluated.
Assuntos
Fotólise , Trimetoprima , Raios Ultravioleta , Poluentes Químicos da Água , Trimetoprima/química , Trimetoprima/toxicidade , Poluentes Químicos da Água/química , Poluentes Químicos da Água/toxicidade , Cinética , Antibacterianos/química , Antibacterianos/toxicidade , Ferro/química , Vácuo , Catálise , AnimaisRESUMO
The synthesis of multifunctional cathode with high-efficiency and stable catalytic activity for simultaneously producing and activating H2O2 is an effective way for promoting the performance of heterogeneous electro-Fenton process (HEF). In addition, accelerating mass transfer by adopting a flow-through reactor is also great importance because of its better utilization of catalysts and adequate contact of the contaminant with the oxidants generated on the electrode surface. Herein, a novel flow-through HEF (FHEF) system was designed for the degradation of trimethoprim (TMP) using bifunctional cathode with a sandwich structure FeOCl nanosheets loaded onto carbon cloth (CC) and activated carbon fiber (ACF) (FeOCl/CC/ACF). The cathode exhibited excellent performance in activating H2O2 for the in-situ generation of hydroxyl radicals (â¢OH). The electron spin resonance (ESR) measurements and radical quenching tests proved that the high production of â¢OH in the FHEF process was favorable to the high catalytic efficiency. 25 mg L-1 TMP was entirely degraded after 60 min, with the TOC removal of 62.6% (180 min) at pH 6.8, 9.0 mA cm-2, and flux rate 210 mL min-1. Moreover, the degradation rate still could reach 83% (60 min) after 10 cycles without obvious valence and crystal phase changes. Simultaneously, the current utilization rate has also been greatly enhanced, with an average current efficiency of 69.9% and a low energy consumption of 0.28 kWh kg-1. The reasonable degradation pathways for TMP were proposed based on the UPLC-QTOF-MS/MS results. Finally, the results of toxicological simulation showed a declining trend in the toxicity of the samples during TMP degradation. These results claim that the FeOCl/CC/ACF-FHEF system is an efficient and economical technology for the treatment of organic contaminants in effluents.
Assuntos
Trimetoprima , Poluentes Químicos da Água , Carvão Vegetal , Poluentes Químicos da Água/análise , Peróxido de Hidrogênio/química , Fibra de Carbono , Espectrometria de Massas em Tandem , Oxirredução , Eletrodos , Concentração de Íons de HidrogênioRESUMO
A comparative degradation of antibiotic cefaclor (CEC) between Ti/Ti4O7 and Ti/RuO2 anodes, in terms of degradation kinetics, mineralization efficiency, and formation of toxic chlorate (ClO3-) and perchlorate (ClO4-), was performed with electrochemical-oxidation (EO), electro-Fenton (EF), and photoelectro-Fenton (PEF) processes. Besides, CEC degradation by EF with boron-doped diamond (BDD) anode was also tested. Results showed CEC decays always followed pseudo-first-order kinetics, with increasing apparent rate constants in the sequence of EO < EF < PEF. The mineralization efficiency of the processes with Ti/Ti4O7 anode was higher than that of Ti/RuO2 anode, but slightly lower than that of BDD anode. Under the optimal conditions, 94.8% mineralization was obtained in Ti/Ti4O7-PEF, which was much higher than 64.4% in Ti/RuO2-PEF. The use of Ti/RuO2 gave no generation of ClO3- or ClO4-, while the use of Ti/Ti4O7 yielded a small amount of ClO3- and trace amounts of ClO4-. Conversely, the use of BDD led to the highest generation of ClO3- and ClO4-. The reaction mechanism was studied systematically by detecting the generated H2O2 and â¢OH. The initial N of CEC was released as NH4+ and, in smaller proportion, as NO3-. Four short-chain carboxylic acids and nine aromatic intermediates were also detected, a possible reaction sequence for CEC mineralization was finally proposed.
Assuntos
Antibacterianos , Poluentes Químicos da Água , Cefaclor , Peróxido de Hidrogênio , Cloratos , Titânio , Percloratos , Oxirredução , Eletrodos , Poluentes Químicos da Água/análiseRESUMO
A novel active Ce-doped Ti4O7 (Ti/Ti4O7-Ce) electrode was prepared and evaluated for improvement of the refractory pollutants degradation efficiency in Electrochemical advanced oxidation processes (EAOPs). The results showed that the addition of Ce in Ti/Ti4O7 electrode leading to great impact on â¢OH generation rate and electrode stability compared to pristine Ti/Ti4O7 electrode. Ti/Ti4O7-Ce electrode presented efficient oxidation capacity for pharmaceutical pollutant atenolol (ATL) in EAOPs, which could be attributed to the improvement of indirect oxidation mediated by electro-generated â¢OH, as the amount of â¢OH production was 16.5% higher than that in Ti/Ti4O7 within 120 min. The operational conditions greatly influenced the ATL degradation. The degradation efficiency of ATL increased as the current density, the degradation efficiency reached 100% under pH 4, but it just removed 81% of ATL under pH 10 after 120 min treatment. Results also suggested that the inhibiting effect from the ATL degradation was mostly associated with the decreased oxidation capacity induced by water hardness and natural organic matter (NOM). It displayed a satisfactory durability after 40 cycles of experimental detections in this research. The results of study suggested that Ti/Ti4O7-Ce was a promising electrode for the efficient degradation of PPCPs-polluted wastewater and provided constructive suggestion for the refractory pollutants of EAOPs.
Assuntos
Atenolol , Poluentes Químicos da Água , Titânio , Poluentes Químicos da Água/análise , Eletrodos , Oxirredução , Preparações FarmacêuticasRESUMO
BACKGROUND: Anhedonia is a core symptom in patients with unipolar and bipolar depression. However, sex-specific markers reflecting biological heterogeneity are lacking. Emerging evidence suggests that sex differences in immune-inflammatory markers and lipoprotein profiles are associated with anhedonia. METHODS: The demographic and clinical data, immune-inflammatory markers (CD3, CD4, and CD8), and lipoprotein profiles [TC, TG, LDL-C, HDL-C, lipoprotein(a) Lp (a)] of 227 patients with unipolar and bipolar depression were collected. The Hamilton Depression Rating Scale (HAMD) and Snaith-Hamilton Pleasure Scale (SHAPS) were used to assess depression and anhedonia symptoms. Data were analyzed using ANOVA, logistic regression, and receiver operating characteristic curves. RESULTS: Male patients in the anhedonia group had higher levels of CD3, CD4, and CD8, and lower levels of Lp (a) than the non-anhedonia group, while no significant difference was identified in female patients with and without anhedonia. Logistic regression analysis showed that CD3, CD4, CD8, and Lp (a) levels were associated with anhedonia in male patients. Furthermore, the combination of CD3, CD4, CD8, and Lp (a) had the strongest predictive value for distinguishing anhedonia in male patients than individual parameters. CONCLUSIONS: We identified sex-specific associations between immune-inflammatory markers, lipoprotein profiles, and anhedonia in patients with unipolar and bipolar depression. The combination of CD3, CD4, CD8, and Lp (a) might be a possible biomarker for identifying anhedonia in male patients with unipolar and bipolar depression.
Assuntos
Anedonia , Transtorno Bipolar , Humanos , Masculino , Feminino , Transtorno Bipolar/diagnóstico , Prazer , Lipoproteínas , BiomarcadoresRESUMO
Circulating tumor cells (CTCs) are associated with metastasis. However, the low rate of detection of CTCs in peripheral vein blood (PVB) limits their clinical application. In this study, we observed higher positive rates of CTC in first drainage vein blood (FDVB) relative to peripheral venous blood (p < 0.001). Moreover, the CTC content was related to liver metastasis, T stage, and CA19-9 levels. Our collective data suggest that CTCs in FDVB have good predictive utility for the risk of liver metastasis of colorectal cancer (CRC), in particular, metachronous liver metastasis.
Assuntos
Neoplasias Colorretais , Neoplasias Hepáticas , Células Neoplásicas Circulantes , Antígeno CA-19-9 , Neoplasias Colorretais/patologia , Drenagem , Humanos , Neoplasias Hepáticas/patologia , Células Neoplásicas Circulantes/patologiaRESUMO
Pulp and paper wastewater (PPWW) contains numerous refractory and harmful contaminants that require advanced treatment to meet the discharge criteria. This study compared the efficacy of two PPWW treatments: ultraviolet/peroxymonosulfate (UV/PMS) and ultraviolet/H2O2 (UV/H2O2) working under similar circumstances. The initial pH value, oxidant dosage, UV radiation intensity, and pseudo-first-order constant kobs were systematically studied in both systems. Optimally, the UV/PMS process produced an effluent of higher quality than the UV/H2O2, as measured by the removal efficiencies of chemical oxygen demand (COD) in 60 min, which were 48.2 and 64.3% for the respective UV/H2O2 and UV/PMS processes and corresponding kobs values of 0.0102 and 0.0159 min-1, respectively. Radical scavenging experiments demonstrated that â¢OH was the primary reactive oxygen species in UV/H2O2 process, and â¢OH and SO4-⢠in the UV/PMS process. Moreover, ultraviolet-visible spectroscopy and gas chromatography coupled mass spectroscopy analyses showed that deep treatment of petroleum hydrocarbons with carbon chain lengths greater than 18 and macromolecular semi-volatile organic compounds in paper wastewater is difficult, whereas the UV/PMS process can significantly improve the removal of amides, esters, phenols, and other aromatic compounds.
Assuntos
Águas Residuárias , Poluentes Químicos da Água , Águas Residuárias/química , Raios Ultravioleta , Peróxido de Hidrogênio/química , Poluentes Químicos da Água/química , OxirreduçãoRESUMO
Lysine demethylase 5B (KDM5B) is up-regulated in many cancers, including breast cancer. However, the underlying metabolic mechanisms of KDM5B on breast cancer progression are poorly understood. Here, we showed that KDM5B expression positively correlates with metastasis in breast cancer. Cell functional analyses were demonstrated that KDM5B knockdown and KDM5B inhibitor AS-8351 inhibited breast cancer cell proliferation and migration. Furthermore, we reported that KDM5B knockdown and AS-8351 reversed epithelial-mesenchymal transition (EMT) and decreased the protein levels of fatty acid synthase (FASN) and ATP citrate lyase (ACLY) in MCF-7 and MDA-MB-231â¯cells. Interestingly, we found that activation of AMP-activated protein kinase (AMPK) signaling pathway is involved in KDM5B-mediated EMT and lipid metabolism reprogramming in breast cancer cells. As a result, silencing of KDM5B-induced activation of AMPK signaling pathway inhibited breast cancer cell proliferation and migration. Taken together, our findings indicated that KDM5B was a novel regulator of lipid metabolism reprogramming, and it was suggested a new strategy to treat breast cancer.
Assuntos
Neoplasias da Mama/metabolismo , Movimento Celular/fisiologia , Histona Desmetilases com o Domínio Jumonji/metabolismo , Metabolismo dos Lipídeos/fisiologia , Proteínas Nucleares/metabolismo , Proteínas Repressoras/metabolismo , Proteínas Quinases Ativadas por AMP/metabolismo , Movimento Celular/efeitos dos fármacos , Proliferação de Células/fisiologia , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Transição Epitelial-Mesenquimal/fisiologia , Feminino , Humanos , Metabolismo dos Lipídeos/efeitos dos fármacosRESUMO
Abnormal metabolism of tumour cells is closely related to the occurrence and development of breast cancer, during which the expression of NF-E2-related factor 2 (Nrf2) is of great significance. Metastatic breast cancer is one of the most common causes of cancer death worldwide; however, the molecular mechanism underlying breast cancer metastasis remains unknown. In this study, we found that the overexpression of Nrf2 promoted proliferation and migration of breast cancers cells. Inhibition of Nrf2 and overexpression of Kelch-like ECH-associated protein 1 (Keap1) reduced the expression of glucose-6-phosphate dehydrogenase (G6PD) and transketolase of pentose phosphate pathway, and overexpression of Nrf2 and knockdown of Keap1 had opposite effects. Our results further showed that the overexpression of Nrf2 promoted the expression of G6PD and Hypoxia-inducing factor 1α (HIF-1α) in MCF-7 and MDA-MB-231 cells. Overexpression of Nrf2 up-regulated the expression of Notch1 via G6PD/HIF-1α pathway. Notch signalling pathway affected the proliferation of breast cancer by affecting its downstream gene HES-1, and regulated the migration of breast cancer cells by affecting the expression of EMT pathway. The results suggest that Nrf2 is a potential molecular target for the treatment of breast cancer and targeting Notch1 signalling pathway may provide a promising strategy for the treatment of Nrf2-driven breast cancer metastasis.
Assuntos
Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Movimento Celular , Glucosefosfato Desidrogenase/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Receptor Notch1/metabolismo , Regulação para Cima , Linhagem Celular Tumoral , Proliferação de Células , Feminino , Humanos , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Modelos Biológicos , Via de Pentose Fosfato , Transdução de SinaisRESUMO
Colorectal cancer (CRC) is the third-leading cause of cancer mortality worldwide. HACE1 function as a tumor-suppressor gene and is downregulated in several kinds of cancers. However, the distribution and clinical significance of HACE1 in CRC is still not clarified. In this study, we found that the HACE1 expression is greatly downregulated in CRC tissues and cell lines. Moreover, the HACE1 expression was significantly associated with inhibition of CRC cell proliferation, metastasis, and invasion. HACE1 inhibited epithelial-mesenchymal transition in CRC cells. Furthermore, we found that HACE1 altered the protein expression of the Hippo pathway by downregulation of YAP1. HACE1 suppresses the invasive ability of CRC cells by negatively regulating the YAP1 pathway. Our data indicates that HACE1 directly targets YAP1 and induces downregulation of YAP1, thereby increasing the activity of the Hippo pathway. In summary, these findings demonstrated that HACE1-YAP1 axis had an important part in the CRC development and progression.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Movimento Celular/genética , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Fatores de Transcrição/genética , Ubiquitina-Proteína Ligases/deficiência , Regulação para Cima/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/genética , Regulação para Baixo/genética , Transição Epitelial-Mesenquimal/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Invasividade Neoplásica , Transdução de Sinais , Fatores de Transcrição/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo , Proteínas de Sinalização YAPRESUMO
Phosphorus (P) recovery from wastewater has been recognized as a critical technology for solving the sustainable supply of this indispensable and non - renewable natural resource. In this study, the cost - free magnesium and calcium sources of using the cooling water system effluent (CWSE) in two thermal power plants were proposed (Z - CWSE and G - CWSE) and the P recovery performance from source - separated urine was investigated. About 90% P recovery efficiency was achieved from the hydrolyzed urine when Z - CWSE and G - CWSE were added at the Ca: Mg: P molar ratios of 3.1 : 4.0: 1 and 3.6 : 3.4: 1, respectively. More than 95% P recovery performance was obtained from the fresh urine as the initial pH of the CWSE - FU mixtures was adjusted to over 9.5 and 10.0, respectively. The precipitates obtained contain 10.84-17.04% Ca, 6.22-9.58% P, 0.75-3.76% Mg and 0.13-0.23% N. XRD analysis confirmed the presence of struvite in the precipitates. The reuse of precipitates is secure due to extremely low contents of heavy metals. The feasibility of using CWSEs as the flushing water in urinals and toilets was assessed. Besides, we proposed CWSEs could be invoked as precipitants in various wastewaters as long as it contains considerable phosphate, e.g. P concentration more than 100â¯mg/L and 50â¯mg/L for Z - CWSE and G - CWSE, respectively.
Assuntos
Fósforo , Água , Compostos de Magnésio , Fosfatos , Estruvita , Urina , Eliminação de Resíduos Líquidos , Águas ResiduáriasRESUMO
Epigenetic modifications such as histone modifications and cytosine hydroxymethylation are linked to tumorigenesis. Loss of 5-hydroxymethylcytosine (5 hmC) by ten-eleven translocation 1 (TET1) down-regulation facilitates tumor initiation and development. However, the mechanisms by which loss of TET1 knockdown promotes malignancy development remains unclear. Here, we report that TET1 knockdown induced epithelial-mesenchymal transition (EMT) and increased cancer cell growth, migration, and invasion in DLD1 cells. Loss of TET1 increased EZH2 expression and reduced UTX-1 expression, thus increasing histone H3K27 tri-methylation causing repression of the target gene E-cadherin. Ectopic expression of the H3K27 demethylase UTX-1 or EZH2 depletion both impeded EZH2 binding caused a loss of H3K27 methylation at epithelial gene E-cadherin promoter, thereby suppressing EMT and tumor invasion in shTET1 cells. Conversely, UTX-1 depletion and ectopic expression of EZH2 enhanced EMT and tumor metastasis in DLD1 cells. These findings provide insight into the regulation of TET1 and E-cadherin and identify EZH2 as a critical mediator of E-cadherin repression and tumor progression.
Assuntos
Caderinas/metabolismo , Movimento Celular , Neoplasias do Colo/metabolismo , Histonas/metabolismo , Oxigenases de Função Mista/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Antígenos CD , Caderinas/genética , Linhagem Celular Tumoral , Proliferação de Células , Neoplasias do Colo/genética , Neoplasias do Colo/patologia , Metilação de DNA , Regulação para Baixo , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Epigênese Genética , Transição Epitelial-Mesenquimal , Regulação Neoplásica da Expressão Gênica , Histona Desmetilases/genética , Histona Desmetilases/metabolismo , Humanos , Oxigenases de Função Mista/genética , Invasividade Neoplásica , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas/genética , Interferência de RNA , Transdução de Sinais , Fatores de Tempo , TransfecçãoRESUMO
Considerable evidence has shown that autophagy has an important role in HIV-1 infection. However, it is still unknown whether metabolism-regulated autophagy pathway is involved in Tat-mediated HIV-1 transactivation. This study demonstrated that treatment of Tat in TZM-bl cells significantly down-regulated protein levels of Beclin-1, Atg-5, Atg-7, and LC3B-II and up-regulated of p62 levels. Blockage of autophagy enhanced Tat-induced HIV-1 transactivation in TZM-bl cells. Moreover, we found that Tat activated the Akt/mTOR and inhibited AMPK signaling pathway that was related to its up-regulation of PKM2 expression. In addition, we showed that PI3K/AKT activation and AMPK inhibtion was required for the PKM2-mediated inhibition of autophagy in Tat-treated TZM-bl cells. In conclusion, our data reveals that PKM2-mediated autophagy inhibition is required for Tat-mediated HIV-1 transactivation. Metabolism-related autophagic pathway may act as a promising diagnostic and therapeutic tool for HIV-1 infection in the future.
Assuntos
Autofagia , Proteínas de Transporte/metabolismo , Infecções por HIV/metabolismo , HIV-1/fisiologia , Proteínas de Membrana/metabolismo , Hormônios Tireóideos/metabolismo , Ativação Transcricional , Produtos do Gene tat do Vírus da Imunodeficiência Humana/metabolismo , Proteínas Quinases Ativadas por AMP/metabolismo , Proteínas de Transporte/genética , Linhagem Celular , Regulação da Expressão Gênica , Infecções por HIV/genética , Infecções por HIV/patologia , Infecções por HIV/virologia , HIV-1/genética , Humanos , Proteínas de Membrana/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo , Hormônios Tireóideos/genética , Proteínas de Ligação a Hormônio da TireoideRESUMO
The effects of polyaluminum chloride (PACl) hydrolysis prior to coagulation on both the coagulation zone and coagulation performance of a kaolin suspension were investigated by a novel jar test named the "reversed coagulation test". The tests showed that PACl hydrolysis prior to coagulation decreased the performance of charge neutralization coagulation in the case of short-time slow mixing (10min; G=15sec-1) and increased the optimal dosage for charge neutralization and sweep coagulation. Moreover, the hydrolysis time had insignificant effects on the size and zeta potential of PACl precipitates and the residual turbidity of the raw water. However, PACl hydrolysis prior to coagulation and the size of PACl precipitates had a negligible effect on the performance of sweep coagulation. The results imply that, in practice, preparing a PACl solution with deionized water, rather than tap water or the outlet water from a wastewater treatment unit, can significantly save PACl consumption and improve the performance of charge neutralization coagulation, while preparing the PACl solution with tap or outlet water would not affect the performance of sweep coagulation. In addition, the optimal rapid mixing intensity appears to be determined by a balance between the degree of coagulant hydrolysis before contacting the primary particles and the average size of flocs in the rapid mixing period. These results provide new insights into the role of PACl hydrolysis and will be useful for improving coagulation efficiency.
Assuntos
Hidróxido de Alumínio/química , Purificação da Água/métodos , Floculação , Hidrólise , CaulimRESUMO
A submerged internal circulating membrane coagulation reactor (MCR) was used to treat surface water to produce drinking water. Polyaluminum chloride (PACl) was used as coagulant, and a hydrophilic polyvinylidene fluoride (PVDF) submerged hollow fiber microfiltration membrane was employed. The influences of trans-membrane pressure (TMP), zeta potential (ZP) of the suspended particles in raw water, and KMnO4 dosing on water flux and the removal of turbidity and organic matter were systematically investigated. Continuous bench-scale experiments showed that the permeate quality of the MCR satisfied the requirement for a centralized water supply, according to the Standards for Drinking Water Quality of China (GB 5749-2006), as evaluated by turbidity (<1 NTU) and total organic carbon (TOC) (<5mg/L) measurements. Besides water flux, the removal of turbidity, TOC and dissolved organic carbon (DOC) in the raw water also increased with increasing TMP in the range of 0.01-0.05MPa. High ZP induced by PACl, such as 5-9mV, led to an increase in the number of fine and total particles in the MCR, and consequently caused serious membrane fouling and high permeate turbidity. However, the removal of TOC and DOC increased with increasing ZP. A slightly positive ZP, such as 1-2mV, corresponding to charge neutralization coagulation, was favorable for membrane fouling control. Moreover, dosing with KMnO4 could further improve the removal of turbidity and DOC, thereby mitigating membrane fouling. The results are helpful for the application of the MCR in producing drinking water and also beneficial to the research and application of other coagulation and membrane separation hybrid processes.
Assuntos
Água Potável/química , Compostos de Manganês/química , Óxidos/química , Purificação da Água/métodos , China , Filtração , Interações Hidrofóbicas e Hidrofílicas , Membranas Artificiais , Oxirredução , Polivinil , Qualidade da ÁguaRESUMO
Acrylonitrile (AN) wastewater is a heavily polluted and a likely hazardous liquid that is generated during the production of AN. Several chemical methods for the pretreatment of AN wastewater are available in laboratory scale. However, the harsh reaction conditions and high operational cost make these methods undesirable. Until now, four-effect evaporation is the only pretreatment method used for AN wastewater in industry despite its huge energy consumption and high cost. It is difficult to find an energy-saving pretreatment technique from the perspective of industrial application. In this study, a safe and low-cost coagulation technique was developed for the pretreatment of AN wastewater. Three types of inorganic coagulant and three types of polymer coagulant were investigated for the coagulation treatment of highly concentrated AN wastewater from petrochemical plants. The effects of coagulant type, dosage, and coagulation conditions on the pretreatment efficiency of AN wastewater were investigated. The results show that a combination of inorganic and polymer coagulants is effective for the pretreatment of AN wastewater.
Assuntos
Acrilonitrila/química , Resíduos Industriais , Petróleo/análise , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/química , Floculação , Concentração de Íons de Hidrogênio , Polímeros/química , Poluentes Químicos da Água/químicaRESUMO
PURPOSE: To use circulating tumor cells (CTC) from the first drainage vein (FDV) of the primary lesion and other clinically relevant parameters to construct a nomogram for predicting liver metastasis in colorectal cancer (CRC) patients, and to provide a theoretical basis for clinical diagnosis and treatment. METHODS: Information from 343 CRC patients was collected and a database was established. Multivariate logistic analysis was used to identify independent factors for colorectal cancer liver metastasis(mCRC) and nomograms were constructed. Receiver operating characteristic curves(ROC), calibration plots, and decision curve analysis (DCA) were used to assess discrimination, agreement with actual risk, and the clinical utility of the prediction model, respectively. RESULT: CTC levels in FDV were significantly higher in patients with liver metastasis than in those without liver metastasis. Logistic multivariate analysis showed that vascular invasion, T stage, carcinoembryonic antigen (CEA), CA19-9, and CTC could be used as predictors to construct nomograms. The nomograms showed good discriminatory ability in predicting mCRC, with area under the curve (AUC) values of 0.871 [95 % CI: 0.817-0.924) and 0.891 (95 % CI: 0.817-0.964) for the training and validation sets, respectively.] The calibration curves of both the training and validation sets showed that the model was effective in predicting the probability of mCRC. DCA was used to evaluate this predictive model and showed good net clinical benefit. CONCLUSION: We developed and validated a nomogram model based on the combination of CTC in the FDV with other clinical parameters to better predict the occurrence of mCRC.
RESUMO
The presence of pharmaceuticals and personal care products (PPCPs) in reclaimed water introduces an ongoing challenge as they infiltrate green space soils during irrigation, leading to a gradual buildup that poses considerable ecological risks. The simulation and forecasting of PPCPs accumulation in soil are pivotal for proactive ecological risk management. However, the majority of research efforts have predominantly concentrated on the vertical transport mechanisms of PPCPs in the soil, neglecting a holistic perspective that integrates both vertical and lateral transport phenomena, alongside accumulation dynamics. To address this gap, this study introduces a comprehensive conceptual model that encapsulates the dual processes of vertical and lateral transport, coupled with accumulation of PPCPs in the soil environment. Grounded in the distinctive properties of green space soils, we delve into the determinants governing the vertical and lateral migration of PPCPs. Furthermore, we consolidate existing simulation methodologies for contaminant transport, aiming to establish a comprehensive model that accurately predicts PPCPs accumulation in green space soils. This insight is critical for deducing the emission threshold of reclaimed water necessary for the protection of green space soils, informing the formulation of rational irrigation strategies, and anticipating future environmental risks. It provides a critical theoretical basis for more informed decision-making in the realm of urban water reuse and pollution control.
Assuntos
Irrigação Agrícola , Reciclagem , Poluentes do Solo , Poluentes do Solo/análise , Preparações Farmacêuticas/análise , Poluentes Químicos da Água/análise , Cosméticos , Solo/química , Modelos Teóricos , CidadesRESUMO
Inspiring the creative potential of overqualified employees can facilitate a mutually beneficial outcome for both the company and the employees. However, further investigation is required to ascertain how to stimulate the perceived overqualification of employees to carry out creative deviance. Drawing upon role theory, this study explores the impact mechanism of perceived overqualification on employee creative deviance, with leadership emergence as the mediating variable, and further examines the moderating role of job autonomy. Adopting a two-stage design, 362 valid data samples were collected from various companies, and analysis was conducted using partial least squares structural equation modeling. The results indicate a positive correlation between perceived overqualification and creative deviance. Perceived overqualification not only positively influences leadership emergence but it also indirectly affects creative deviance through leadership emergence. Furthermore, when individuals with perceived overqualification and possess a greater level of job autonomy, they are more likely to engage in creative deviant behavior. The findings contribute to understanding the mediating mechanisms and boundary conditions of employees' perceived overqualification influencing creative deviance from a positive perspective, offering valuable managerial insights for organizations.