Optimization of conventional Fenton and ultraviolet-assisted oxidation processes for the treatment of reverse osmosis retentate from a paper mill

According to current environmental legislation concerned with water scarcity, paper industry is being forced to adopt a zero liquid effluent policy. In consequence, reverse osmosis (RO) systems are being assessed as the final step of effluent treatment trains aiming to recover final wastewater and reuse it as process water. One of the most important drawbacks of these treatments is the production of a retentated stream, which is usually highly loaded with biorecalcitrant organic matter and inorganics; and this effluent must meet current legislation stringent constraints before being ultimately disposed. The treatment of biorefractory RO retentate from a paper mill by several promising advanced oxidation processes (AOPs) - conventional Fenton, photo-Fenton and photocatalysis - was optimized considering the effect and interaction of reaction parameters; particularly using response surface methodology (RSM) when appropriate (Fenton processes). The economical cost of these treatments was also comparatively assessed. Photo-Fenton process was able to totally remove the COD of the retentate, and resulted even operatively cheaper at high COD removal levels than conventional Fenton, which achieved an 80% reduction of the COD at best. In addition, although these optimal results were produced at pH=2.8, it was also tested that Fenton processes are able to achieve good COD reduction efficiencies (>60%) without adjusting the initial pH value, provided the natural pH of this wastewater was close to neutral. Finally, although TiO(2)-photocatalysis showed the least efficient and most expensive figures, it improved the biodegradability of the retentate, so its combination with a final biological step almost achieved the total removal of the COD.     

Thermal valorisation of automobile shredder residue: injection in blast furnace

Wastes with residual heating value, according to the trend of the world legislation, could be thermally reused. The present study is conducted to verify the possibility of thermal valorisation of a waste, denominated fluff, by injection in blast furnace. The fluff, arising from the automobile shredder operations, is a waste characterised by a high organic matrix and is potentially dangerous due to the heavy metals, oils filter and halogenated plastics content. The first step of the work is the chemical, physical and toxicological characterisation of this material. Then the fluff injection in a blast furnace tuyere is theoretically analysed with a mathematical model. Finally, experimental trials are conducted in a pilot plant, simulating the most important part of the blast furnace: the raceway, in order to analyse process and industrial aspects. In view of an industrial application a first economical evaluation is carried out on the basis of model and experimental results.     

An international review of local governance for climate change: implications for Hong Kong

Cities have increasingly become the focal point for climate change initiatives. However, how cities respond to climate change challenges and through what mechanisms have remained largely unexplored. This paper develops a framework for local governance to examine and explain climate change initiatives in cities. Based on the analysis of 20 climate change initiatives in major cities and a detailed case study of Hong Kong, this paper has two main findings. First, local governments at the city level have an important role to play in climate change policies by embracing some key strategies (such as deliberation and partnership) and values (such as equity and legitimacy) of good governance. Second, by comparing and contrasting the experience in other cities, our case study of Hong Kong provides insights about the barriers that may limit a city's ability to adapt to new forms of governance that would enable it to better respond to climate change. The paper concludes by exploring the potential role of local governance as a model to strengthen climate change initiatives at the city level.     

Association of arsenic and kidney dysfunction in people with diabetes and validation of its effects in rats

We studied villagers with and without diabetes from arsenic-endemic areas and a nearby control site in Xinjiang Autonomous Region, PR China. Water and urinary arsenic were assayed for exposure measurement. Urinary NAG (N-acetyl-beta-glucosaminidase), a kidney function test, blood glucose, triglyceride, cholesterol, high density lipid and low density lipid were measured. Villagers from endemic areas were found to have higher urinary arsenic concentrations. The NAG results also suggest that chronic arsenic exposure presents a significant adverse impact on the kidney function of villagers in the endemic areas. However, blood glucose levels of diabetes individuals were lower than those from the control site. These observations were validated in rats which were chronically exposed to arsenic in drinking water. The distinct relationship between chronic arsenic exposure and diabetes mellitus requires further investigation. A rodent model is a useful tool for study of this type.     

Nitrite and nitrate induced photodegradation of monolinuron in aqueous solution

Here we evidenced the photo-induced degradation of monolinuron, a phenylurea herbicide, through the 300–450 nm light excitation of nitrite and nitrate species. The degradation pathways were compared to those obtained under direct photolysis at 254 nm. When using NO₃^– and NO₂^– as photoinducers, hydroxyphenyl-substituted photodegradation products were found to be formed specifically through the involvement of OH° radicals. NO^– and NO₂-phenyl substituted compounds were also observed as a result of the production of NO° and NO₂° radicals. Half-lives of monolinuron in aqueous solutions were measured in various conditions of concentrations of substrate and inducer, oxygen content and pH.     

Declining extra-pair paternity with laying order associated with initial incubation behavior,but independent of final clutch size in the blue tit

Although functional explanations for female engagement in extra-pair copulation have been studied extensively in birds, little is known about how extra-pair paternity is linked to other fundamental aspects of avian reproduction. However, recent studies indicate that the occurrence of extra-pair offspring may generally decline with laying order, possibly because stimulation by eggs induces incubation, which may suppress female motivation to acquire extra-pair paternity. Here we tested whether experimental inhibition of incubation during the laying phase, induced by the temporary removal of eggs, resulted in increased extra-pair paternity, in concert with a later cessation of laying, in blue tits (Cyanistes caeruleus). As expected, experimental females showed a more gradual increase in nocturnal incubation duration over the laying phase and produced larger clutches than controls. Moreover, incubation duration on the night after the first egg was laid predicted how extra-pair paternity declined with laying order, with less incubation being associated with more extra-pair offspring among the earliest eggs in the clutch. However, incubation duration on this first night was unrelated to our experimental treatment and independent of final clutch size. Consequently, the observed decline in extra-pair paternity with laying order was unaffected by our manipulation and larger clutches included proportionally fewer extra-pair offspring. We suggest that female physiological state prior to laying, associated with incubation at the onset of laying, determines motivation to acquire extra-pair paternity independent of final clutch size. This decline in proportion of extra-pair offspring with clutch size may be a general pattern within bird species.     

Natural sunlight NO(3)(-)/NO(2)(-)-induced photo-degradation of phenylurea herbicides in water

The nitrate-induced photodegradation of phenylureas in water was demonstrated to occur efficiently using natural sunlight irradiation. The kinetics of disappearance was found to be dependent on the inducer and substrate concentrations, the phenylurea structure and the origin and composition of the aqueous matrix including the presence of nitrite. The measured effects under sunlight were of the same order of those measured previously in the lab using our solar light simulated system. However, by-product distribution might differ substantially particularly considering the nitration pathway.     

CDC's research portfolio in older adult fall prevention: a review of progress, 1985-2005, and future research directions

PROBLEM: Falls are a leading cause of mortality and morbidity among adults age 65 and older. Population models predict steep increases in the 65 and older population bands in the next 10-15 years and in turn, public health is bracing for increased fall rates and the strain they place on health care systems and society. To assess progress in fall prevention, the Centers for Disease Control and Prevention conducted a research portfolio review to examine the quality, relevance, outcomes and successes of the CDC fall prevention program and its impact on public health. METHODS: A peer review panel was charged with reviewing 20 years of funded research and conducting a SWOT (strengths, weaknesses, opportunities, and threats) analysis for extramural and intramural research activities. Information was collected from grantees (via a survey instrument), staff were interviewed, and progress reports and products were reviewed and analyzed. RESULTS: CDC has invested over $24,900,000 in fall-related research and programs over 20 years. The portfolio has had positive impacts on research, policies and programs, increasing the public health injury prevention workforce, and delivering effective fall prevention programs. DISCUSSION: Public health agencies, practitioners, and policy makers recognize that while there are some evidence-based older adult fall prevention interventions available, many remain unused or are infeasible to implement. Specific recommendations across the public health model, include: additional research in gathering robust epidemiologic data on trends and patterns of fall-related injuries at all levels; researching risk factors by setting or sub-population; developing and testing innovative interventions; and engaging in translation and dissemination research on best practices to increase uptake and adoption of fall prevention strategies. CDC has responded to a number of suggestions from the portfolio review including: funding translation research of a proven Tai Chi fall intervention; beginning to address gaps in gender, ethnic, and racial differences in falls; and collaborating with partner organizations who share in CDC's mission to improve public health by preventing falls and reducing fall-related injuries. IMPACT ON INDUSTRY: Industry has an opportunity to develop more accessible and usable devices to reduce injury from falls (for example, hip protectors and force reducing flooring). By implementing effective, evidence-based interventions to prevent falls and reduce injuries from falls, significant decreases in health care costs can be expected.