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1.
Ecotoxicol Environ Saf ; 159: 28-37, 2018 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-29730406

RESUMEN

In the present study, impact of coagulant activity of zirconium oxychloride and aluminium sulphate on the kinetics of chlorine consumption and trihalomethanes (THMs) formation has been delineated. Zirconium Oxychloride showed rapid chlorine decay within the first 30 min, which further achieved steady rate after 60 min, but in case of aluminium sulphate chlorine consumption has been increased drastically throughout the chlorine decay. Zirconium oxychloride has effectively reduced significant amount of slow reducing agents (SRA) as well as fast reducing agents (FRA), which correspond to the rate of reduction in phenolic groups from water enriched with Natural Organic Matter (NOM) which eventually decreased trihalomethane mediated cancer risk by ~ 2.3 times among adults as compared to aluminium sulphate. Result depicts the outstanding coagulant activity of zirconium oxychloride as it tends to surpass aluminium sulphate in reducing NOM "measured as Absorbance Slope Index (ASI)" and phenol by 57.98% and 49.02% respectively from NOM enriched chlorinated water, which also resembles the THMs removal trend observed during cancer risk assessment.


Asunto(s)
Trihalometanos/química , Contaminantes Químicos del Agua/química , Purificación del Agua/métodos , Circonio/química , Compuestos de Alumbre/química , Cloro/química , Floculación , Halogenación , Cinética
2.
J Environ Sci (China) ; 70: 1-10, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-30037396

RESUMEN

Reactivity of chlorine towards hydrophobic groups present in natural organic matter (NOM) provokes the formation of carcinogenic disinfection byproducts such as trihalomethanes in chlorinated water. The present study aimed to investigate the variations in coagulant activity of alum using two different bioflocculants (coagulant aid) namely, Moringa oleifera and Cyamopsistetragonoloba for the removal of hydrophobic fractions of NOM and subsequent chlorine consumption by treated water. Effect of dual coagulants on trihalomethane surrogate parameters such as total organic carbon, dissolved organic carbon, UV absorbing materials and prominent hydrophobic species such as phenolic groups along with aromatic chromophores, polyhydroxy aromatic moiety have also been studied. The concept of differential spectroscopy and absorbance slope index has been employed to understand the combined effects of alum-bioflocculants on the reactivity of NOM with chlorine. Our result shows that the combination of alum and C. tetragonoloba is more efficient for reducing trihalomethane surrogates from chlorinated water as compared to M. oleifera. C. tetragonoloba elicited synchronized effects of sweep coagulation and particle bridging-adsorption which eventually facilitated efficient removal of hydrophobic fractions of NOM. The variation in the mechanistic approach of bioflocculants was due to the presence of cationic charge on M. oleifera and adhesive property of C. tetragonoloba.


Asunto(s)
Compuestos de Alumbre/química , Trihalometanos/química , Contaminantes Químicos del Agua/química , Purificación del Agua/métodos , Adsorción , Desinfección , Interacciones Hidrofóbicas e Hidrofílicas , Trihalometanos/análisis , Contaminantes Químicos del Agua/análisis
3.
Health Serv Insights ; 16: 11786329231189407, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37533503

RESUMEN

Background: Pneumonia is one of the leading causes of death in under-5 children in India. This led the Ministry of Health & Family Welfare (MoHFW) in India to decide for the nationwide roll-out of the Pneumococcal Conjugate Vaccine (PCV). However, the introduction of PCV became more complex in the face of unprecedented challenges set forth by the COVID-19 pandemic. The study aims to assess enablers and barriers to the introduction of PCV in India during the pandemic. Methodology: Qualitative research approach involving key-informant interviews from John Snow India (JSI), the lead technical agency that supported MoHFW in the PCV expansion was employed to delineate the enablers and barriers. Principle of saturation was employed to derive the sample size. Thematic analysis using inductive approach was based on the modified World Health Organization (WHO) framework for new vaccine introduction impact on the Immunization and Health Systems, using NVIVO 12 qualitative data analysis software. Results: A total of 11 key informants (4 national-level program managers and 7 state technical officers) were telephonically interviewed. The study found social acceptance, lower cost of the vaccine, and intensive communication activities as potential enablers. Other enablers for PCV introduction included a robust vaccine supply-chain system, ample cold-chain space availability, and strong political commitment, despite the ongoing second wave. Further, the identified barriers included poor physical access, insufficient social mobilization, and limited advocacy along with a stretched workforce. Conclusion: The study delineated several enablers and barriers to introducing PCV in the country during the pandemic. The existing barriers in the PCV roll-out prompted the need to address these gaps, making key program-based recommendations to improve future new vaccine introductions during the pandemic.

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