RESUMEN
Propaquizafop is a highly efficient aryloxy phenoxy propionate chiral herbicide. However, the use of propaquizafop, including its safe use methods, residue patterns, dietary risk assessment, and maximum residue limits, for ginseng, a traditional Chinese medicinal plant, has not been studied. An analytical method was established for the simultaneous determination of propaquizafop and its four metabolites in ginseng soil, fresh ginseng, ginseng plant, and dried ginseng using HPLC-MS/MS. This approach showed good linearity (R2 ranging from 0.9827 to 0.9999) and limit of quantification ranging from 0.01 to 0.05 mg/kg. The intra- and interday recovery rates of this method ranged from 71.6 to 107.1% with relative standard deviation ranging from 1.3 to 23.2%. The method was applied to detect residual samples in the field, and it was found that the degradation of propaquizafop in ginseng plants and soil followed a first-order kinetic equation. R2 was between 0.8913 and 0.9666, and the half-life (t1/2) ranged from 5.04 to 8.05 days, indicating that it was an easily degradable pesticide (T1/2 < 30 days). The final propaquizafop residues in ginseng soil, plants, fresh ginseng, and dried ginseng ranged from 0.017 to 0.691 mg/kg. A dietary risk assessment was conducted on the final propaquizafop residue in fresh and dried ginseng. The results showed that the chronic exposure risk quotient values were less than 100% for fresh and dried ginseng (1.15% for fresh ginseng and 1.13% for dried ginseng). This illustrates that the dietary risk associated with the use of 10% propaquizafop emulsifiable concentrate in ginseng is very low. Thus, applying 750 mL/ha of propaquizafop on ginseng could not pose an unacceptable risk to public health. The results of the present study support the registration of propaquizafop in ginseng.
Asunto(s)
Panax , Residuos de Plaguicidas , Contaminantes del Suelo , Espectrometría de Masas en Tándem/métodos , Panax/química , Residuos de Plaguicidas/análisis , Contaminantes del Suelo/química , Medición de Riesgo , Semivida , Suelo/química , ChinaRESUMEN
Electric arc furnace (EAF) slag aggregate, a waste by-product of the steel industry, exhibited a high potential for phosphorus (P) removal and had attracted considerable attention. The main objectives of this study were to evaluate the performance of using EAF slag aggregate as an adsorbent for P removal and identify its P removal capacity. A series of batch tests showed that P removal capacity of EAF slag increases gradually with the increase of pH with a range of 2-10, while the highest P removal capacity (1.94â mg/g) can be obtained at pH 12. The adsorption kinetics of P on EAF slag can be described by pseudo-second-order kinetic equations. Isothermal adsorption simulations showed that the best fitted model was the Freundlich model with a correlation coefficient of 0.9825. A continuous flow column experiment feeding a synthetic influent containing 15â mg P/L was operated for 60 days and the P removal efficiency was greater than 95% with a P removal capacity of 1.6â mg P/g slag. The results obtained in this study showed that EAF slag could act as an efficient adsorbent for P removal. Calcium phosphate precipitation depends on the release of Ca2+ and OH- by the dissolution of calcium oxide in EAF slag was found to be the dominant removal mechanism for P removal.
Asunto(s)
Fósforo , Aguas Residuales , Adsorción , Residuos Industriales/análisis , AceroRESUMEN
OBJECTIVE: The EORTC QOL Group has recently completed the cross-cultural development and validation of a standalone measure of spiritual well-being (SWB) for cancer patients receiving palliative care: the EORTC QLQ-SWB32. The measure includes four scales: Relationships with Others, Relationship with Self, Relationship with Someone or Something Greater, and Existential, plus a Global-SWB item. This paper reports on further research investigating relationships between sex, age and SWB for patients receiving palliative care for cancer-adjusting for other socio-demographic, clinical and function variables, including WHO performance status and EORTC QLQ-C15-PAL emotional and physical function scores. METHODS: Cross-sectional data from the validation study were used, and chi-square, independent t tests, Mann-Whitney U tests and multiple regression analyses applied. RESULTS: The study included 451 participants with advanced and incurable cancer, from 14 countries. Adjusted analyses found better scores for female participants than males on three of the four EORTC QLQ-SWB32 subscales; Relationship with others, Relationship with Someone or Something Greater and Existential plus Global-SWB. Older age was positively associated with better Relationship with Self. CONCLUSION: The findings from our participants suggest that it might be beneficial if healthcare providers seeking to address patients' spiritual needs pay particular attention to male patients, younger patients and those with poor emotional functioning.
Asunto(s)
Neoplasias/psicología , Cuidados Paliativos , Espiritualidad , Encuestas y Cuestionarios/normas , Factores de Edad , Anciano , Estudios Transversales , Emociones , Existencialismo , Femenino , Humanos , Relaciones Interpersonales , Masculino , Persona de Mediana Edad , Análisis Multivariante , Neoplasias/terapia , Calidad de Vida , Autoimagen , Factores Sexuales , Factores SocioeconómicosRESUMEN
Salt ions are ubiquitous in wastewater and have significant impacts on the microbial activity and nitrogen and phosphorus removal in biological wastewater treatment processes. The effects of KCl salinity on the removal of COD, TN and PO43--P were investigated in a lab-scale A2O process. Meanwhile, the effects of K+ concentration on the composition of extracellular polymeric substances (EPS) and the microbial community structure were demonstrated. The results showed that the pollutant removal efficiencies and the bioactivity of the activated sludge decreased and the EPS content enhanced under high concentration of K+, which resulted in the deterioration of sludge compactness and settleability. The microbial diversity reduced after K+ addition and the microbial community structure was distinct between the system with (10â¯gâ¯L-1 and 40â¯gâ¯L-1) and without K+ addition. The relative abundance of Candidatus-Competibacter, Acinetobacter and Azoarcus decreased in the anoxic zone with the increase of K+ concentration, which might led to the decrease in denitrifying phosphorus removal capacity. However, the relative abundance of some genera of Firmicutes (such as Fusibacter, Acetoanaerobium, Planococcus and Exiguobacterium) increased, which was coincident with the enhanced microbial salt-tolerance capacity. Proteobacteria, Bacteroides, Chloroflexi and Firmicutes were the dominant phyla irrespective of the salinity changed, which guaranteed the removal of organic compounds, nitrogen and phosphorus in salty environment.
Asunto(s)
Potasio/química , Eliminación de Residuos Líquidos/métodos , Reactores Biológicos/microbiología , Desnitrificación , Microbiota , Nitrógeno , Compuestos Orgánicos , Fósforo , Salinidad , Aguas del Alcantarillado/microbiología , Aguas Residuales/químicaRESUMEN
In order to improve the biological removal efficiency of nitrogen and phosphorus and bioflocculation performance of salt-containing wastewater, the effect of NaCl salinity on the efficiency of denitrification and phosphorus removal in the anoxic zone of an A2/O process was investigated. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) were used to analyze the composition and structure of extracellular polymeric substances (EPS) in activated sludge of the anoxic zone, to discern the effect of salinity on bioflocculation. Results showed that when NaCl salinity was 0-5 g·L-1, flocculation ability (FA) in A2/O anoxic zone was about 44% and the sludge particle size was 45.5 µm. EPS content increased from 52.3 mg·L-1 to 62 mg·L-1 and protein (PN)/polysaccharide (PS) remained at 2.1. When NaCl salinity increased from 10 g·L-1 to 40 g·L-1, bioflocculation of sludge significantly decreased. FA decreased from 40% to 22% and sludge particle size decreased from 43.7 µm to 32.1 µm. EPS content increased from 76.5 mg·L-1 to 101.0 mg·L-1 and PN/PS decreased from 1.5 to 1.3. Based on FTIR analysis, with increase in salinity, the main components of EPS were always amino, amideâ , and carboxyl. Based on XPS analysis, increasing salinity led to charge transfer of some groups (such as C, O, and N groups) during the interaction between EPS and Na+, but its form did not change.
Asunto(s)
Matriz Extracelular de Sustancias Poliméricas/química , Salinidad , Aguas del Alcantarillado/química , Eliminación de Residuos Líquidos , Reactores Biológicos , Floculación , Nitrógeno/aislamiento & purificación , Fósforo/aislamiento & purificación , Cloruro de Sodio , Aguas ResidualesRESUMEN
The traditional two-stage anoxic-oxic (A/O) activated sludge process might be inefficient in pollutants removal and could not ensure the effluent quality. By installing polyurethane foams as carriers and inoculating specialized bacteria in the oxic compartments, the activated sludge systems could be transformed into bioaugmented biofilm processes to enhance the removal efficiency to recalcitrant pollutants. Optimal environment should be provided for the bioaugmented bacteria during systems' start-up. In the present research, dissolved oxygen (DO) concentration was studied as a crucial environmental factor on the performances of the bioagumented systems. The results indicated that the system adopted lower DO concentration took less time to start-up, performed higher pollutants removal efficiency and stronger resistance to shock loadings compared to the system with higher DO level. This was the first attempt to evaluate the importance of DO concentration on the start-up of the two-stage bioaugmented A/O biofilm process.
Asunto(s)
Bacterias Anaerobias/fisiología , Biopelículas , Biotecnología/métodos , Residuos Industriales/prevención & control , Petróleo/microbiología , Aguas del Alcantarillado/microbiología , Eliminación de Residuos Líquidos/métodos , Purificación del Agua/métodos , Biodegradación Ambiental , Reactores Biológicos , Arquitectura y Construcción de Instituciones de Salud , Filtración , Oxígeno/química , Compuestos de Amonio Cuaternario/química , Aguas del Alcantarillado/química , Contaminantes Químicos del Agua/análisisRESUMEN
In this paper, bioaugmentation was applied to upgrade a full-scale activated sludge system (S2) into a contact oxidation system (S1). Results showed that when chemical oxygen demand (COD) and ammonia nitrogen (NH(4)(+)-N) concentration of the petrochemical wastewater were 320-530 mg/L and 8-25mg/L, respectively, the bioaugmented process (S1) took only 20 days when they were below 80 mg/L and 10mg/L, respectively. However, the unbioaugmented conventional activated sludge process (S2) spent 30 days to reach the similar effluent quality. As the organic loading rate (OLR) increased from 0.6 to 0.9 and finally up to 1.10 kg COD/m(3)d, S1 showed strong resistance to shock loadings and restored after three days compared to the seven days required by S2. Based on the results of this paper, it shows that bioaugementation application is feasible and efficient for the process upgrade due to the availability of the bioaugmented specialized consortia.