RESUMEN
Textile industries contribute to water pollution through synthetic dye discharge. This study explores the use of natural bio-coagulants to remove acid dyes from wastewater, investigating factors like pH, coagulant dose, dye concentration, contact time, and temperature for optimal results. The optimum pH and coagulants capabilities of (CAAPP, CAAPH, CBAGL, CBAPP and CBAPH) were 3 (49.6 mg/g), 3 (42.5 mg/g), 3 (38.9 mg/g), 4 (35.7 mg/g), 4 (34.1 mg/g), and 4 (29.4 mg/g) respectively, while treating of selected BRF-221 dyes from water solution. The acidic range (3-4) was found to have the best pH for the maximal coagulation, and the optimal dose were found to be 0.05 g/50 mL. The equilibrium was attained within 45-60 min for all coagulants. After 60 min of shaking, the maximum coagulation capacities (21.9, 21.02, 16.5, 27.9, 25.3, and 23.4 mg/g) of several coagulant composites (CAAGL, CAAPP, CAAPH, CBAGL, CBAPP, CBAPH) were determined. The initial BRF-221 dye concentration in the range of 10-200 mg/L was considered as optimum for gaiting maximum elimination of dye using different coagulants. At a dye value of 100 mg/L of BRF-221, maximal coagulation capacities CAAGL (179.19 mg/g), CAAPP (166.06 mg/g), CAAPH (141.60 mg/g), and CBAGL (126.49 mg/g), CBAPP (113.9 mg/g), CBAPH (93.08 mg/g) were attained. The study found 35 °C to be the optimal temperature for maximum acid dye removal using bio-coagulants. Increasing temperature reduced coagulation capacity, indicating an exothermic process. Freundlich and Langmuir isotherms showed suitability for pseudo-first-order and pseudo-second-order kinetics in biosorption. Thermodynamic parameters were assessed for process feasibility. Effective coagulants demonstrated sensitivity to electrolyte variations. In column studies, adjusting parameters achieved maximum coagulation efficiency for removing BRF-221 dyes. The study successfully applied optimal parameters to remove real textile effluents at a practical scale. SEM, FT-IR, BET and XRD characterized coagulants, providing insights into stability and morphology.
Asunto(s)
Compuestos de Alumbre , Bentonita , Colorantes , Contaminantes Químicos del Agua , Purificación del Agua , Compuestos de Alumbre/química , Bentonita/química , Contaminantes Químicos del Agua/química , Adsorción , Purificación del Agua/métodos , Colorantes/química , Concentración de Iones de Hidrógeno , Eliminación de Residuos Líquidos/métodos , Aguas Residuales/química , Silicatos de Aluminio/química , Floculación , Arcilla/químicaRESUMEN
BACKGROUND: Breast cancer (BC) is one of the major causes of death worldwide. It is the most common cause of death before the age of 70 years. The incidence and mortality of BC are rapidly increasing, posing great challenges to the health system and economy of every nation. METHODOLOGY: A cross-sectional analytical study was conducted at the Department of Pathology and Clinical Laboratory of the French Medical Institute for Mothers and Children (FMIC) to demonstrate the association of human epidermal growth factor receptor 2 (Her2/Neu) and estrogen receptor (ER)/ progesterone receptor (PR) with clinical as well as pathological parameters among women with BC. A consecutive nonprobability sampling method was used for this study over a span of one and a half years. RESULTS: One hundred twenty participants diagnosed with breast cancer were included in the study. The mean age at diagnosis was 44.58 ± 11.16 years. Out of the total patients, 68 (56.7%) were above 40 years old, 108 (90%) were married, 94 (78.3%) were multiparous, and 88 (73.3%) had a history of breastfeeding. 33.3% of cases were within the age range of menopause (40-50 years). The positive expression rates of ER, PR, and Her2/neu were found to be 48.8%, 44.6%, and 44.6%, respectively, and Her2/neu overexpression was found to be higher among ER/PR-negative cases. CONCLUSION: In our study, we demonstrated that among Afghan women, grade II invasive ductal carcinoma, not otherwise specified, was the most common type of BC and frequently affected women above the age of 40. We also revealed that the percentage of negative ER (50.4%), negative PR (54.4%), and concordant ER/PR-negative cases were high compared to other possibilities. Additionally, the study revealed that expression of Her2/neu was in contrast with the expression of ER and PR receptors. The findings of our study still support the importance of performing immunohistochemical stains for hormonal receptor classification in terms of better clinical outcomes and prognosis.
Asunto(s)
Neoplasias de la Mama , Receptor ErbB-2 , Adulto , Anciano , Femenino , Humanos , Persona de Mediana Edad , Afganistán/epidemiología , Biomarcadores de Tumor/metabolismo , Neoplasias de la Mama/epidemiología , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Estudios Transversales , Hormonas , Receptor ErbB-2/metabolismo , Receptores de Progesterona/metabolismo , Centros de Atención TerciariaRESUMEN
Industries generate hazardous dye wastewater, posing significant threats to public health and the environment. Removing dyes before discharge is crucial. The ongoing study primarily focused on synthesizing, applying, and understanding the mechanism of green nano-biochar composites. These composites, including zinc oxide/biochar, copper oxide/biochar, magnesium oxide/biochar, and manganese oxide/biochar, are designed to effectively remove Actas Pink-2B (Direct Red-31) in conjunction with constructed wetlands. Constructed wetland maintained pH 6.0-7.9. At the 10th week, the copper oxide/biochar treatment demonstrated the highest removal efficiency of total suspended solids (72%), dissolved oxygen (7.2 mg/L), and total dissolved solids (79.90%), followed by other biochar composites. The maximum removal efficiency for chemical oxygen demand (COD) and color was observed at a retention time of 60 days. The electrical conductivity also followed the same order, with a decrease observed up to the 8th week before becoming constant. A comprehensive statistical analysis was conducted, encompassing various techniques including variance analysis, regression analysis, correlation analysis, and principal component analysis. The rate of color and COD removal followed a second-order and first-order kinetics, respectively. A significant negative relationship was observed between dissolved oxygen and COD. The study indicates that employing biochar composites in constructed wetlands improves textile dye removal efficiency.
The novelty of this study is the selection of Cymbopogon as a proper plant for phytoremediation of dye along with green metal oxide coated biochar. These were selected due to their good ability to remove organic pollutant. This study demonstrates the uptake and degradation processes of persistent dye in constructed wetland.
Asunto(s)
Carbón Orgánico , Colorantes , Nanocompuestos , Eliminación de Residuos Líquidos , Contaminantes Químicos del Agua , Humedales , Eliminación de Residuos Líquidos/métodos , Biodegradación Ambiental , Aguas Residuales/química , Análisis de la Demanda Biológica de Oxígeno , Compuestos AzoRESUMEN
Advanced oxidation/reduction processes (AO/RPs) are considered as effective water treatment technologies and thus could be used to solve the problem of water pollution. These technologies of wastewater treatment involve the production of highly reactive species such as â¢OH, Hâ¢, e-aq, SO4â¢-, and SO3â¢-. These radicals can attack the targeted contaminants present in aqueous media and result in their destruction. The efficiency of AO/RPs is highly affected by various operational parameters such as initial concentration of contaminant, solution pH, catalyst amount, intensity of light source, nature of oxidant and reductant used, and the presence of various ionic species in aquatic media. Among AO/RPs, the solar light-based AO/RPs are most widely used nowadays for contaminant removal from aqueous media because of their high environmental friendliness and cost effectiveness. By using these techniques, almost all types of pollutants can be easily removed from aquatic media within short intervals of time, and hence, the problem of water pollution can be solved effectively. This review focuses on various AO/RPs used for wastewater treatment. The effects of different operational parameters that affect the efficiency of these processes toward contaminant removal have been discussed. Besides, challenges and future recommendations are also briefly provided for the researchers in order to improve the efficiency of these processes.
Asunto(s)
Contaminantes Químicos del Agua , Purificación del Agua , Oxidación-Reducción , Luz Solar , Purificación del Agua/métodos , Catálisis , Contaminantes Químicos del Agua/análisisRESUMEN
Organochlorine pesticides (OCPs) have been used extensively as insecticides and herbicides. This study investigates the occurrence of lindane in surface water from the Peshawar valley (i.e., Peshawar, Charsadda, Nowshera, Mardan and Swabi districts of Khyber Pakhtunkhwa, Pakistan). Out of 75 samples tested (i.e., 15 samples from each district), 13 samples (including 2 from Peshawar, 3 from Charsadda, 4 from Nowshera, 1 from Mardan, and 3 from Swabi) are found to be contaminated with lindane. Overall, the detection frequency is 17.3%. The maximum concentration of lindane is detected in a water sample from Nowshera and found to be 2.60 µg L-1. Furthermore, the degradation of lindane in the water sample from Nowshera, containing the maximum concentration, is investigated by simulated solar-light/TiO2 (solar/TiO2), solar/H2O2/TiO2 and solar/persulfate/TiO2 photocatalysis. The degradation of lindane by solar/TiO2 photocatalysis is 25.77% after 10 h of irradiation. The efficiency of the solar/TiO2 process is significantly increased in the presence of 500 µM H2O2 and 500 µM persulfate (PS) (separately), represented by 93.85 and 100.00% lindane removal, respectively. The degradation efficiency of lindane is lower in natural water samples as compared to Milli-Q water, attributed to water matrix effect. Moreover, the identification of degradation products (DPs) shows that lindane follows similar degradation pathways in natural water samples as the one in Milli-Q water. The results show that the occurrence of lindane in surface waters of Peshawar valley is a matter of great concern for human beings and the environment. Interestingly, H2O2 and PS assisted solar/TiO2 photocatalysis is an effective method for the removal of lindane from natural water.
RESUMEN
Local perceptions and understanding of the causes of ill health and death can influence health-seeking behaviour and practices in pregnancy. We aimed to understand individual explanatory models for stillbirth in Afghanistan to inform future stillbirth prevention. This was an exploratory qualitative study of 42 semi-structured interviews with women and men whose child was stillborn, community elders, and healthcare providers in Kabul province, Afghanistan between October-November 2017. We used thematic data analysis framing the findings around Kleinman's explanatory framework. Perceived causes of stillbirth were broadly classified into four categories-biomedical, spiritual and supernatural, extrinsic factors, and mental wellbeing. Most respondents attributed stillbirths to multiple categories, and many believed that stillbirths could be prevented. Prevention practices in pregnancy aligned with perceived causes and included engaging self-care, religious rituals, superstitious practices and imposing social restrictions. Symptoms preceding the stillbirth included both physical and non-physical symptoms or no symptoms at all. The impacts of stillbirth concerned psychological effects and grief, the physical effect on women's health, and social implications for women and how their communities perceive them. Our findings show that local explanations for stillbirth vary and need to be taken into consideration when developing health education messages for stillbirth prevention. The overarching belief that stillbirth was preventable is encouraging and offers opportunities for health education. Such messages should emphasise the importance of care-seeking for problems and should be delivered at all levels in the community. Community engagement will be important to dispel misinformation around pregnancy loss and reduce social stigma.
RESUMEN
In this research work, surface-modified nano zerovalent copper (nZVC) was prepared using a simple borohydride reduction method. The spectroscopic and crystallographic results revealed the successful synthesis of surface-modified nano zerovalent copper (nZVC) using solvents such as ethanol (ETOH), ethylene glycol (EG) and tween80 (T80). The as-synthesized material was fully characterized for morphological surface and crystal structural properties. The results indicated that EG provides an excellent synthesis environment to nZVC compared to ETOH and T80 in terms of good dispersion, high surface area and excellent catalytic properties. The catalytic efficiency of nZVC/EG was investigated alone and with peroxymonosulphate (PMS) in the absence of light. The degradation results demonstrated that the involvement of PMS synergistically boosted the catalytic efficiency of synthesized nZVC/EG material. Furthermore, the degradation products (DPs) of CBZ were determined by GC-MS and subsequently, the degradation pathways were proposed. The ecotoxicity analysis of the DPs was also explored. The proposed (nZVC/EG/PMS) system is economical and efficient and thus could be applied for the degradation of CBZ from an aquatic system after altering the degradation pathways in such a way that results in harmless products.
RESUMEN
This study is focused on synthesis of highly efficient Titania/reduced Graphene Oxide (TiO2/rGO) nanocomposites by means of simple hydrothermal technique. The TiO2/rGO were synthesized in different ratios of 0.5, 1.0, 2.0, and 3% by varying the concentration of rGO while the concentration of TiO2 was kept constant and the obtained samples were designated as TrG0.5, TrG1, TrG2, and TrG3 respectively. Different characterization techniques (SEM, TEM, HRTEM, XRD, EDX, TGA, UV-DRS, PL, EIS, and BET) showed high crystallinity, small crystallite size (18.4 nm), high thermal stability, high purity, low band gap energy (Eg = 3.12 eV), and high surface area (65.989 m2/g) for the as-synthesized TiO2/rGO nanocomposite. The efficiencies of TiO2/rGO were determined in terms of brilliant green (BG) dye degradation in aqueous media under UV light. The results revealed that 2% TiO2/rGO (TrG2) showed high efficiency for BG degradation with the kapp of 0.023 min-1 compared to TiO2 alone (kapp of 0.006 min-1). The rate of BG degradation was further synergised by the addition of peroxymonosulfate (PMS) to the system. The degradation of BG was improved to 99.4% by the incorporation of PMS in aqueous media compared to TrG2 alone. Furthermore, the degradation of BG was also examined in various media (neutral, acidic, and basic). The results revealed that by increasing pH of the medium from 3.85 to 8.2 the degradation of BG was enhanced from 99.4 to 99.9% with the corresponding kapp of 0.0602 min-1. Moreover, the photocatalytic degradation of BG followed the pseudo-first-order kinetics. Radical scavenging experiments showed that âOH and SO4â- were the main species responsible for the degradation of BG under UV light. Besides, for determining the efficiency of as-synthesized TrG2/PMS system, the degradation of BG was also performed in various water types (distilled water, tape water, synthetic wastewater, and industrial wastewater). The degradation products (DPs) of BG and their corresponding pathways were proposed, accordingly.
Asunto(s)
Nanocompuestos , Contaminantes Químicos del Agua , Óxidos/química , Aguas Residuales , Contaminantes Químicos del Agua/química , Agua , Titanio/química , Nanocompuestos/químicaRESUMEN
Purpose: Cancer is one of the leading causes of mortality and morbidity, and therefore, tremendous research work is continuously being done around the world with consideration of etiopathogenesis as well as identification of therapeutic targets. Decades of continuous war in Afghanistan has left the medical infrastructure of the country in a miserable situation. There is a serious deficiency in research work in the fields of pathology and oncology at the moment with minimal data available to elaborate about the demographic characteristics of various malignant disorders in the country, which would be indispensable to pave the way for further research and development. Patients and Methods: A descriptive cross-sectional study was conducted to describe the prevalence, distribution, and important histopathological features of malignant tumors reported at tertiary level in Afghanistan. Results: Out of 2328 consecutive cases of solid malignant tumors included in our study, 93.8% were primary and 6.2% were metastatic. Breast was the most common site of origin for primary malignancy (29.5%) in females; however, in males, esophagus was the leading site for primary malignant tumors (16.3%). Invasive ductal carcinoma was the most common histologic type of malignancy in females (87.9%). However, in both genders, squamous cell carcinoma of esophagus and skin, osteosarcoma of bone and soft tissue, and glioblastoma of central nervous system were the most common histologic types of malignancies diagnosed. Small intestine was a frequently involved site affected by extranodal non-Hodgkin lymphomas. Overall, the majority of the cancers were diagnosed in stage-II. Conclusion: Findings in our study were somewhat similar to data presented elsewhere in the world, with some significant differences that could be related to the local factors. Our study revealed that most of the malignant tumors were diagnosed in later stages of the disease, attributable to scarcity of specialized oncology institutions and public awareness.
RESUMEN
Binary composite of zerovalent iron and titanium dioxide (Fe0/TiO2) was synthesized for the catalytic removal of dichlorophene (DCP) in the presence of peroxymonosulfate (PMS). The as-prepared composite (Fe0/TiO2) exhibits synergistic effect and enhanced properties like improved catalytic activity of catalyst and greater magnetic property for facile recycling of catalyst. The results showed that without addition of PMS at reaction time of 50 min, the percent degradation of DCP by TiO2, Fe0, and Fe0/TiO2 was just 5%, 11%, and 12%, respectively. However, with the addition of 0.8 mM PMS, at 10 min of reaction time, the catalytic degradation performance of Fe0, TiO2, and Fe0/TiO2 was significantly improved to 82%, 18%, and 88%, respectively. The as-prepared catalyst was fully characterized to evaluate its structure, chemical states, and morphology. Scanning electron microscopy results showed that in composite TiO2 causes dispersion of agglomerated iron particles which enhances porosity and surface area of the composites and X-ray diffraction (XRD), energy dispersive X-ray (EDX), and Fourier-transform infrared (FTIR) results revealed successful incorporation of Fe0, and oxides of Fe and TiO2 in the composite. The adsorption-desorption analysis verifies that the surface area of Fe0/TiO2 is significantly larger than bare Fe0 and TiO2. Moreover, the surface area, particle size, and crystal size of Fe0/TiO2 was surface area = 85 m2 g-1, particle size = 0.35 µm, and crystal size = 0.16 nm as compared to TiO2 alone (surface area = 22 m2 g-1, particle size = 4.25 µm, and crystal size = 25.4 nm) and Fe0 alone (surface area = 65 m2 g-1, particle size = 0.9 µm, and crystal size = 7.87 nm). The as-synthesized material showed excellent degradation performance in synthesized wastewater as well. The degradation products and their toxicities were evaluated and the resulted degradation mechanism was proposed accordingly. The toxicity values decreased in order of DP1 > DP5 > DP2 > DP3 > DP4 and the LC50 values toward fish for 96-h duration decreased from 0.531 to 67.2. This suggests that the proposed technology is an excellent option for the treatment of antibiotic containing wastewater.
Asunto(s)
Diclorofeno , Hierro , Animales , Antibacterianos , Catálisis , Hierro/química , Estrés Oxidativo , Peróxidos , Titanio/química , Aguas Residuales , AguaRESUMEN
This study reported Fe doped zinc oxide (Fe-ZnO) synthesis to degrade chlorpyrifos (CPY), a highly toxic organophosphate pesticide and important sources of agricultural wastes. Fourier transform infrared, X-ray diffraction, scanning electron microscope, and energy-dispersive X-ray spectroscopic analyses showed successful formation of the Fe-ZnO with highly crystalline and amorphous nature. Water collected from agricultural wastes were treated with Fe-ZnO and the results showed 67% degradation of CPY by Fe-ZnO versus 39% by ZnO at 140 min treatment time. Detail mechanism involving reactive oxygen species production from solar light activated Fe-ZnO and their role in degradation of CPY was assessed. Use of H2O2, peroxydisulfate (S2O82-) and peroxymonosulfate (HSO5-) with Fe-ZnO under solar irradiation promoted removal of CPY. The peroxides yielded hydroxyl (OH) and sulfate radical () under solar irradiation mediated by Fe-ZnO. Effects of several parameters including concentration of pollutant and oxidants, pH, co-existing ions, and presence of natural organic matter on CPY degradation were studied. Among peroxides, HSO5- revealed to provide better performance. The prepared Fe-ZnO showed high reusability and greater mineralization of CPY. The GC-MS analysis showed degradation of CPY resulted into several transformation products (TPs). Toxicity analysis of CPY as well as its TPs was performed and the formation of non-toxic acetate imply greater capability of the treatment technology.
Asunto(s)
Cloropirifos , Óxido de Zinc , Catálisis , Cloropirifos/toxicidad , Peróxido de Hidrógeno , Difracción de Rayos XRESUMEN
Kisspeptin has an important role in the stimulation of hypothalamic-pituitary-gonadal axis in term of pubertal development, release of reproductive and metabolic hormones and ultimately affecting the fertility. The aim of the present study was to evaluate the serum kisspeptin level and its correlation with semen quality and selected hormones in buffalo bulls during the summer and spring seasons. Semen and blood samples from eight Nili-Ravi buffalo bulls (age: 9.21 ± 1.02 years) were collected. Semen was analysed using computer-assisted semen analysis. Serum concentrations of kisspeptin, gonadotropin releasing hormone (GnRH), follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone, cortisol, triiodothyronine (T3), thyroxin (T4) and insulin like growth factor (IGF-1) were estimated using enzyme-linked immunosorbent assay kits. Kisspeptin was neither affected by seasons and nor correlated with semen parameters and hormones. Higher levels of GnRH, LH, cortisol, IGF-1, total motility (TM), average path velocity (VAP), straight-line velocity (VSL), curvilinear velocity (VCL) and linearity (LIN) were recorded in summer compared to spring. Correlations of GnRH versusIGF-1 and LH, LH versus IGF-1 and cortisol, FSH versus T4 and testosterone, testosterone versus T3 and T4 and T3 versus T4 were observed. The GnRH and IGF-1 were positively associated with TM, VAP, VSL, VCL and LIN. The LH was correlated with VSL, straightness and LIN. In conclusion, GnRH, LH, and IGF-1 correlations with semen parameters can be used to indicate semen quality. The buffalo bulls are well-adapted and can give quality semen in the summer season.
RESUMEN
In this work, bismuth-doped titania (BixTiO2) with improved oxygen vacancies was synthesized by sol-gel protocol as a novel peroxymonosulfate (PMS, HSO5-) activator. HSO5- and adsorbed oxygen molecules could efficiently be transformed into their respective radicals through defect ionization to attain charge balance after their trapping on oxygen vacancies of the catalyst. XRD study of BixTiO2 with 5 wt% Bi (5BiT) revealed anatase, crystalline nature, and successful doping of Bi into TiO2 crystal lattice. The particle size obtained from BET data and SEM observations was in good agreement. PL spectra showed the formation rates of â¢OH by 3BiT, 7BiT, 5BiTC, and 5BiT as 0.720, 1.200, 1.489, and 2.153 µmol/h, respectively. 5BiT catalyst with high surface area (216.87 m2 g-1) and high porosity (29.81%) was observed the excellent HSO5- activator. The catalytic performance of 0BiT, 3BiT, 5BiT, and 7BiT when coupled with 2 mM HSO5- for recalcitrant flumequine (FLU) removal under dark was 10, 27, 55, and 37%, respectively. Only 5.4% decrease in catalytic efficiency was observed at the end of seventh cyclic run. Radical scavenging studies indicate that SO4â¢- is the dominant species that caused 62.0% degradation. Moreover, strong interaction between Bi and TiO2 through Bi-O-Ti bonds prevents Bi leaching (0.081 mg L-1) as shown by AAS. The kinetics, degradation pathways, ecotoxicity, and catalytic mechanism for recalcitrant FLU were also elucidated. Cost-efficient, environment-friendly, and high mineralization recommends this design strategy; BixTiO2/HSO5- system is a promising advanced oxidation process for the aquatic environment remediation.
Asunto(s)
Bismuto , Oxígeno , Peróxidos , TitanioRESUMEN
OBJECTIVE: This study aimed to explore bereaved parents' and healthcare providers experiences of care after stillbirth. STUDY DESIGN: Qualitative in-depth interviews with 55 women, men, female elders, healthcare providers and key informants in Kabul province, Afghanistan between October and November 2017. RESULTS: Inadequate and insensitive communication and practices by healthcare providers, including avoiding or delaying disclosing the stillbirth were recurring concerns. There was a disconnect between parents' desires and healthcare provider's perceptions. The absence of shared decision-making on seeing and holding the baby and memory-making, manifested as profound regret. Health providers' reported hospitals were not equipped to separate women who had a stillbirth and acknowledged that psychological support would be beneficial. However, the absence of trained personnel and resource constraints prevented provision of such support. CONCLUSION: Findings can inform future provision of perinatal bereavement care. Given resource constraints, communication training can be considered with longer term goals to develop context-appropriate bereavement care guidelines.
Asunto(s)
Aflicción , Mortinato , Afganistán , Anciano , Femenino , Personal de Salud , Humanos , Masculino , Padres , Embarazo , Investigación CualitativaRESUMEN
This study reports the comparative removal of an emerging contaminant diclofenac sodium (DCF) by UV-254â nm-based advanced oxidation processes (AOPs), i.e. UV/S2O82-/Fe2+, UV/HSO5-/Fe2+ and UV/H2O2/Fe2+ processes. The results demonstrated that by applying [DCF]0 = 0.30â mM and [H2O2]0 = [S2O82-]0 = [HSO5-]0 = 3â mM, kapp values were 0.082, 0.166, 0.221, 0.485 and 2.014â min-1 for UV-only, UV/Fe2+, UV/H2O2/Fe2+, UV/S2O82-/Fe2+ and UV/HSO5-/Fe2+ processes, respectively. At different [DCF]0 from 0.30 to 0.90â mM, the degradation rate was increased from 0.01â mMâ min-1 to 0.12â mMâ min-1, while the corresponding kapp values were decreased from 2.01â min-1 to 1.04â min-1. The removal performance of the applied AOP was significantly influenced by the presence of natural water contaminants (NO3-, Cl-, HCO3-, SO42- and humic acid (HA)) and [pH]0. The inhibition of these natural water contaminants on the removal of DCF by UV/HSO5-/Fe2+ process was in the order of HA > NO2- > SO42- > HCO3- ≈ Cl- > NO3-. Furthermore, seven (07) degradation products (DPs) of DCF were explored by UPLC-MS/MS and accordingly degradation pathways of DCF were suggested. The practical applications of the proposed AOPs towards the removal of DCF were further strengthened by calculating total organic carbon removal and toxicity assessment.
Asunto(s)
Diclofenaco , Contaminantes Químicos del Agua , Cromatografía Liquida , Peróxido de Hidrógeno , Cinética , Espectrometría de Masas en Tándem , Rayos Ultravioleta , Contaminantes Químicos del Agua/análisisRESUMEN
Congo-red (CR), a precursor of textile products and a contaminant of great concern, has contaminated aquatic environments. Here, we explored the synthesis of mesoporous nano-zerovalent manganese (nZVMn) and Phoenix dactylifera leaves biochar (PBC) composite for the removal of CR from water. The nZVMn/PBC adsorbed 117.647 mg/g of CR versus 25.316 mg/g by PBC at [CR]0 = 20 mg/L and [PBC]0 = [nZVMn/PBC]0 = 500 mg/L. Variation of [nZVMn/PBC]0, [CR]0 and pH influenced the adsorption of CR. Freundlich adsorption isotherm and pseudo-first-order kinetic models best fitted CR adsorption. The H2O2 coupling with nZVMn/PBC promoted removal of CR possibly due to the formation of hydroxyl radical (âOH) and caused 95 % removal of CR versus 77 % by nZVMn/PBC alone. The âOH scavengers inhibited the removal of CR. The nZVMn/PBC showed a good reusability and efficient removal of CR up to the seventh cycle of treatment. Results reveal that nZVMn improved performance, thermal stability and reusability of biochar. Degradation products from âOH-mediated degradation of CR were studied by ultraperformance liquid chromatography with mass spectrometric detector to establish degradation pathways. The ion-chromatographic analysis showed the formation of non-toxic inorganic acetate product, which suggests high potential of the newly fabricated adsorbent in the removal of CR.
Asunto(s)
Rojo Congo , Contaminantes Químicos del Agua , Adsorción , Carbón Orgánico , Congo , Peróxido de Hidrógeno , Concentración de Iones de Hidrógeno , Cinética , Manganeso , Estrés Oxidativo , Soluciones , Agua , Contaminantes Químicos del Agua/análisisRESUMEN
In this study, we showed that doping bismuth (Bi) at the surface of Fe0 (Bi/Fe0, bimetallic iron system)-synthesized by a simple borohydride reduction method-can considerably accelerate the reductive degradation of chloramphenicol (CHP). At a reaction time of 12 min, 62, 68, 74, 95, and 82% degradation of CHP was achieved with Fe0, Bi/Fe0-1 [1% (w/w) of Bi], Bi/Fe0-3 [3% (w/w) of Bi], Bi/Fe0-5 [5% (w/w) of Bi], and Bi/Fe0-8 [8% (w/w) of Bi], respectively. Further improvements in the degradation efficiency of CHP were observed by combining the peroxymonosulfate (HSO5 -) with Bi/Fe0-5 (i.e., 81% by Bi/Fe0-5 and 98% by the Bi/Fe0-5/HSO5 - system at 8 min of treatment). Interestingly, both Fe0 and Bi/Fe0-5 showed effective H2 production under dark conditions that reached 544 and 712 µM by Fe0 and Bi/Fe0-5, respectively, in 70 mL of aqueous solution containing 0.07 g (i.e., at 1 g L-1 concentration) of the catalyst at ambient temperature.
RESUMEN
BACKGROUND: The underlying pathways leading to stillbirth in low- and middle-income countries are not well understood. Context-specific understanding of how and why stillbirths occur is needed to prioritise interventions and identify barriers to their effective implementation and uptake. AIM: To explore the contribution of contextual, individual, household-level and health system factors to stillbirth in Afghanistan. METHODS: Using a qualitative approach, we conducted semi-structured in-depth interviews with women and men that experienced stillbirth, female elders, community health workers, healthcare providers, and government officials in Kabul province, Afghanistan between October-November 2017. We used thematic analysis to identify contributing factors and developed a conceptual map describing possible pathways to stillbirth. FINDINGS: We found that low utilisation and access to healthcare was a key contributing factor, as were unmanaged conditions in pregnancy that increased women's risk of complications and stillbirth. Sociocultural factors related to the treatment of women and perceptions about medical interventions deprived women of interventions that could potentially prevent stillbirth. The quality of care from public and private providers during pregnancy and childbirth was a recurring concern exacerbated by health system constraints that led to unnecessary delays; while environmental factors linked to the ongoing conflict were also perceived to contribute to stillbirth. These pathways were underscored by social, cultural, economic factors and individual perceptions that contributed to the three-delays. DISCUSSION: Efforts are needed at the community-level to facilitate care-seeking and raise awareness of stillbirth risk factors and the facility-level to strengthen antenatal and childbirth care quality, ensure culturally appropriate and respectful care, and reduce treatment delays.
Asunto(s)
Parto Obstétrico/estadística & datos numéricos , Muerte Fetal/prevención & control , Accesibilidad a los Servicios de Salud/estadística & datos numéricos , Atención Perinatal/estadística & datos numéricos , Calidad de la Atención de Salud , Mortinato , Adulto , Afganistán , Anciano , Niño , Femenino , Personal de Salud , Humanos , Recién Nacido , Entrevistas como Asunto , Parto , Aceptación de la Atención de Salud , Embarazo , Investigación Cualitativa , Factores de Riesgo , Población UrbanaRESUMEN
Quality concerns exist with stillbirth data from low- and middle-income countries including under-reporting and misclassification which affect the reliability of burden estimates. This is particularly problematic for household survey data. Disclosure and reporting of stillbirths are affected by the socio-cultural context in which they occur and societal perceptions around pregnancy loss. In this qualitative study, we aimed to understand how community and healthcare providers' perceptions and practices around stillbirth influence stillbirth data quality in Afghanistan. We collected data through 55 in-depth interviews with women and men that recently experienced a stillbirth, female elders, community health workers, healthcare providers, and government officials in Kabul province, Afghanistan between October-November 2017. The results showed that at the community-level, there was variation in local terminology and interpretation of stillbirth which did not align with the biomedical categories of stillbirth and miscarriage and could lead to misclassification. Specific birth attendant practices such as avoiding showing mothers their stillborn baby had implications for women's ability to recall skin appearance and determine stillbirth timing; however, parents who did see their baby, had a detailed recollection of these characteristics. Birth attendants also unintentionally misclassified birth outcomes. We found several practices that could potentially reduce under-reporting and misclassification of stillbirth; these included the cultural significance of ascertaining signs of life after birth (which meant families distinguished between stillbirths and early neonatal deaths); the perceived value and social recognition of a stillborn; and openness of families to disclose and discuss stillbirths. At the facility-level, we identified that healthcare provider's practices driven by institutional culture and demands, family pressure, and socio-cultural influences, could contribute to under-reporting or misclassification of stillbirths. Data collection methodologies need to take into consideration the socio-cultural context and investigate thoroughly how perceptions and practices might facilitate or impede stillbirth reporting in order to make progress on data quality improvements for stillbirth.
Asunto(s)
Cultura , Recolección de Datos , Revelación/estadística & datos numéricos , Personal de Salud/psicología , Características de la Residencia , Mortinato/psicología , Adulto , Afganistán , Países en Desarrollo , Femenino , Humanos , Entrevistas como Asunto , Masculino , Madres , Embarazo , Investigación Cualitativa , Reproducibilidad de los Resultados , Encuestas y CuestionariosRESUMEN
Removal of cadmium (Cd2+), a highly toxic heavy metal, from aqueous solutions was investigated using nano zerovalent iron (Fe0). Cadmium was efficiently removed by Fe0, although reactivity and reusability of Fe0 was significantly promoted by coupling with bismuth (Bi). At a reaction time of 20â¯min, 85% and 96% Cd2+ was removed by Fe0 and Bi/Fe0, respectively, at first cycle using [Cd2+]0â¯=â¯10â¯mg/L and [Fe0]0â¯=â¯[Bi/Fe0]0â¯=â¯1.0â¯g/L. However, Cd2+ removal efficiency was reduced to 12% and 80% at sixth cycle by Fe0 and Bi/Fe0, respectively. The X-Ray diffraction and energy dispersive X-Ray spectroscopy analysis proved successful formation of Fe0 by the chemical reduction method and also confirmed coupling of Bi with Fe0 to form bimetallic Bi/Fe0. The oxidation of Fe0 and Bi/Fe0 yielded electron that played significant role in the conversion of toxic Cd2+ into non-toxic Cd0. The reactivity of electron with Cd2+ was calculated to be 4.3â¯×â¯109â¯M-1â¯s-1. The pH of solution showed pronounced effects on the reactivity of both Fe0 and Bi/Fe0. Removal of Cd2+ by both Fe0 and Bi/Fe0 followed pseudo-first-order kinetic model. The conversion of Cd2+ into non-toxic Cd0 proved Fe0 and Bi/Fe0 to be highly efficient and rewarding in detoxification of Cd2+ and other toxic metals in aqueous environments.