Household arsenic contaminated water treatment employing iron oxide/bamboo biochar composite: An approach to technology transfer.

Commercialization of novel adsorbents technology for providing safe drinking water must consider scale-up methodological approaches to bridge the gap between laboratory and industrial applications. These imply complex matrix analysis and large-scale experiment designs. Arsenic concentrations up to 200-fold higher (2000 µg/L) than the WHO safe drinking limit (10 µg/L) have been reported in Latin American drinking waters. In this work, biochar was developed from a single, readily available, and taxonomically identified woody bamboo species, Guadua chacoensis. Raw biochar (BC) from slow pyrolysis (700 °C for 1 h) and its analog containing chemically precipitated Fe3O4 nanoparticles (BC-Fe) were produced. BC-Fe performed well in fixed-bed column sorption. Predicted model capacities ranged from 8.2 to 7.5 mg/g and were not affected by pH 5-9 shift. The effect of competing matrix chemicals including sulfate, phosphate, nitrate, chloride, acetate, dichromate, carbonate, fluoride, selenate, and molybdate ions (each at 0.01 mM, 0.1 mM and 1 mM) was evaluated. Fe3O4 enhanced the adsorption of arsenate as well as phosphate, molybdate, dichromate and selenate. With the exception of nitrate, individually competing ions at low concentration (0.01 mM) did not significantly inhibit As(V) sorption onto BC-Fe. The presence of ten different ions in low concentrations (0.01 mM) did not exert much influence and BC-Fe's preference for arsenate, and removal remained above 90%. The batch and column BC and BC-Fe adsorption capacities and their ability to provide safe drinking water were evaluated using a naturally contaminated tap water (165 ± 5 µg/L As). A 960 mL volume (203.8 Bed Volumes) of As-free drinking water was collected from a 1 g BC-Fe fixed bed. Adsorbent regeneration was attempted with (NH4)2SO4, KOH, or K3PO4 (1 M) strippers. Potassium phosphate performed the best for BC-Fe regeneration. Safe disposal options for the exhausted adsorbents are proposed. Adsorbents and their As-laden analogues (from single and multi-component mixtures) were characterized using high resolution XPS and possible competitive interactions and adsorption pathways and attractive interactions were proposed including electrostatic attractions, hydrogen bonding and weak chemisorption to BC phenolics. Stoichiometric precipitation of metal (Mg, Ca and Fe) oxyanion (phosphate, molybdate, selenate and chromate) insoluble compounds is considered. The use of a packed BC-Fe cartridge to provide As-free drinking water is presented for potential commercial use. BC-Fe is an environmentally friendly and potentially cost-effective adsorbent to provide arsenic-free household water.

How much would low- and middle-income countries benefit from addressing the key risk factors of road traffic injuries?

Despite strong advocacy, the UN Decade of Action for Road Safety (2011-2020) is ending with most low- and middle-income countries (LMICs) no closer to the Sustainable Development Goals target of reducing traffic mortality by half. In contrast, most high-income countries (HICs) have seen large benefits in recent decades from large-scale safety interventions. We aimed to assess how much LMICs would benefit from interventions that address six key risk factors related to helmet use, seatbelt use, speed control, drink driving, and vehicle design for safety of occupants and pedestrians. We use a comparative risk assessment framework to estimate mortality and health loss (disability adjusted life years lost, DALYs) that would be averted if these risks were reduced through intervention. We estimate effects for six countries that span all developing regions: China, Colombia, Ethiopia, India, Iran, and Russia. We find relatively large benefits (27% reductions in road traffic deaths and DALYs) from speed control in all countries, and about 5%-20% reductions due to other interventions depending on who is at risk in each country. To achieve larger gains, LMICs would need to move beyond simply learning from HICs and undertake new research to address risk factors particularly relevant to their context.

Safety of motorized two-wheeler riders in the formal and informal transport sector.

Road fatalities are largely preventable problem with large socioeconomic impact. Due to the rapidly increasing population, transport systems and road infrastructure have not met the demand. The use of motorized two-wheeler vehicles has increased, as informal transport. However, evidence on their safety is scarce. The aim of this article is to examine the safety and social equity issues in MTW in the informal transport sector. Factors can be used to explain traffic collisions in MTW in the formal/informal transport sectors: design, rider behavior, road design, enforcement, and regulation of the informal transport sector. Evidence suggests that MTWs could be a common related to pedestrian fatalities. Informal transport drivers are typically poor, uneducated, young men who due to lack of other employment options move into the informal sector. Their vehicles are old, unmaintained and have a lack of protective equipment for themselves and their passengers. Young, male drivers speed, take risks and not use protective equipment. Users of informal transport live in the poorer peripheries of cities, which, have limited, inefficient or unaffordable public transport. The provision of transport has therefore become an often unrecognized, important social equity issue and studies are urgently needed on MTW in the informal transport sector.

Traffic safety and city structure: lessons for the future.

OBJECTIVE: To understand the critical factors that are likely to influence road traffic fatality rates in large cities around the world in the next few decades. MATERIAL AND METHODS: Road traffic fatality data for 56 cities around the world and for cities with a population of greater than 100,000 in the USA were collected and analysed to understand factors affecting differences in fatality rates. RESULTS: There are wide variations in fatality rates across income levels and within similar incomes levels. The risk varies by a factor of about 20 between the best and the worst cities. CONCLUSIONS: These patterns appear to indicate that it is not enough to have the safest vehicle and road technology to ensure low road traffic fatality rates. City structure, modal share split, and exposure of motorists and pedestrians may have a significant role in determining fatality rates, in addition to enforcement, vehicle crashworthiness and road design.

Traffic safety and city structure: lessons for the future: [review]

OBJECTIVE: To understand the critical factors that are likely to influence road traffic fatality rates in large cities around the world in the next few decades. MATERIAL AND METHODS: Road traffic fatality data for 56 cities around the world and for cities with a population of greater than 100 000 in the USA were collected and analysed to understand factors affecting differences in fatality rates. RESULTS: There are wide variations in fatality rates across income levels and within similar incomes levels. The risk varies by a factor of about 20 between the best and the worst cities. CONCLUSIONS: These patterns appear to indicate that it is not enough to have the safest vehicle and road technology to ensure low road traffic fatality rates. City structure, modal share split, and exposure of motorists and pedestrians may have a significant role in determining fatality rates, in addition to enforcement, vehicle crashworthiness and road design.

OBJETIVO: Entender los factores críticos con probabilidad de influir en las tasas de fatalidad por tránsito en las grandes ciudades del mundo durante las próximas décadas. MATERIAL Y MÉTODOS: Se recolectaron y analizaron datos de fatalidad por tránsito de 56 ciudades del mundo y de las ciudades en Estados Unidos con más de 100 000 habitantes para entender aquellos factores que determinan diferencias en las tasas de fatalidad. RESULTADOS: Hay grandes variaciones en las tasas de fatalidad entre diferentes niveles de ingreso y dentro de niveles de ingreso similares. El riesgo varía por un factor de alrededor de 20 entre las mejores y las peores ciudades. CONCLUSIÓN: Estos patrones parecen indicar que no es suficiente tener vehículos y tecnologías viales más seguros para asegurar tasas bajas de fatalidad por tránsito. La estructura de la ciudad, el reparto modal del transporte y la exposición de los automovilistas y peatones pueden tener un papel significativo en la determinación de las tasas de fatalidad, además de la aplicación de los reglamentos, la protección de los vehículos contra impacto y el diseño de las vialidades.