可持续生产与消费方式:因素与挑战

21世纪议程将不可持续发展的生产与消费方式,尤其是在发达国家,确定为全球环境恶化的主要原因.虽然大部分的问题源于发达国家,但是世界上最贫穷的地区却在承受最严重的后果.在当今的全球市场中,发展中国家会承受越来越多的由于生产落后而导致的社会以及环境影响.     

The effects of magnesium and ammonium additions on phosphate recovery from greenhouse wastewater

Phosphorus recovery from greenhouse wastewater, using precipitation-crystallization, was conducted under three levels of calcium concentration, 304 mg/L (7.6 mmol/L), 384 mg/L (9.6 mmol/L), and 480 mg/L (12 mmol/L), and also with additions of ammonium and magnesium into the wastewater. Jar test results confirmed high phosphate removal, with more than 90% of the removal achieved with a pH as low as 7.7. Under the low calcium concentration, ammonium addition affected the chemical reactions at pH lower than 8.0, where struvite was produced; when the pH was raised to 8.8, other calcium compounds dominated the precipitation. Under the medium calcium concentration, ammonium and magnesium addition helped struvite precipitation in the low pH range. Hydroxyapatite (HAP) was the main product. Under the high calcium concentration, ammonium addition showed no effects on the precipitation.     

Planktonic larval duration of one hundred species of Pacific and Atlantic damselfishes (Pomacentridae)

The plankton larval duration for 100 species of Pacific and Atlantic damselfishes was estimated from daily growth increments on the otolith of juvenile fish collected at various localities between July 1987 and September 1988. For newly-settled fishes, larval duration was determined by counting the entire number of increments present on the otolith, while for older juveniles estimates were made by counting the number of increments between the center of the otolith and a mark corresponding to settlement. We document the development of otolith formation during the period when eggs are incubated on the reef and show that daily increments are only accreted after larvae hatch and enter the planktonic phase. The planktonic larval duration for damselfish is shorter and less variable, both between and within species, compared to other groups of reef fishes such as wrasses and surgeonfishes. Larval duration ranged from 12 to 39 d. Average duration between species ranged from 13.1 to 35.2 d. The time spent in the plankton was not significantly correlated with geographic distribution when evaluated among species, however, genera with confined regional distribution have a shorter mean larval life than do widely distributed genera. Size at settlement was positively correlated with time spent in the plankton among species, but a significant correlation between these variables was only evident within one of ten species. The low variance in planktonic larval duration within species indicates that most damselfish are unable to delay metamorphosis following competency. This inability to postpone settlement limits the potential for dispersal, especially when dispersal time between suitable habitats is greater than about 30 d.     

Interpolation performance of a spatio-temporal model with spatially varying coefficients: application to PM<Subscript>10</Subscript> concentrations in Rio de Janeiro

In this work we present a Bayesian analysis in linear regression models with spatially varying coefficients for modeling and inference in spatio-temporal processes. This kind of model is particularly appealing in situations where the effect of one or more explanatory processes on the response present substantial spatial heterogeneity. We describe for this model how to make inference about the regression coefficients and response processes under two scenarios: when the explanatory processes are known throughout the study region, and when they are known only at the sampling locations. Using a simulation experiment we investigate how parameter inference and interpolation performance are affected by some features of the data and prior distribution that is used. The proposed methodology is used to model the dataset on PM₁₀ levels in the metropolitan region of Rio de Janeiro presented in Paez and Gamerman (2003).     

Cadmium,zinc and total mercury levels in the tissues of several fish species from La Plata river estuary,Argentina

A survey of the concentrations of heavy metals — cadmium, zinc and total mercury — in the tissues of fifteen fish species from Samborombón Bay, La Plata river estuary, in Argentina, has been carried out. Liver appeared to be the main organ accumulating cadmium and zinc, while both liver and muscle showed a similar ability for accumulating mercury. The bioaccumulation process was verified for the three metals analyzed, even though low concentrations have been determined. The biomagnification process of the metals studied was not verified in this environment. The highest metal concentrations were recorded in Mugil liza, and particulate matter and sediments — which are closely related to its trophic and ecological habits — seemed to be the main source of metals for this species. Both Micropogonias furnieri and Mugil liza were recognized as possible indicator species for future monitoring programmes for heavy metals in Samborombón Bay. Considering the present results, this area of La Plata river estuary is characterized as a non-polluted environment.Scientific Researcher from the National Council for Scientific and Technological Researches (CONICET), of Argentina     

Ambient toxicity due to chlorpyrifos and diazinon in a central California coastal watershed

The Salinas River watershed along the central coast of California, U.S.A., supports rapidly growing urban areas and intensive agricultural operations. The river drains to an estuarine National Wildlife Refuge and a National Marine Sanctuary. The occurrence, spatial patterns, sources and causesof aquatic toxicity in the watershed were investigated by sampling four sites in the main river and four sites in representative tributaries during 15 surveys between September1998 and January 2000. In 96 hr toxicity tests, significant Ceriodaphnia dubia mortality was observed in 11% of the mainriver samples, 87% of the samples from a channel draining anurban/agricultural watershed, 13% of the samples fromchannels conveying agricultural tile drain runoff, and in 100% of the samples from a channel conveying agricultural surface furrow runoff. In six of nine toxicity identificationevaluations (TIEs), the organophosphate pesticides diazinon and/or chlorpyrifos were implicated as causes of observed toxicity, and these compounds were the most probable causes oftoxicity in two of the other three TIEs. Every sample collectedin the watershed that exhibited greater than 50% C. dubia mortality (n = 31) had sufficient diazinon and/or chlorpyrifos concentrations to account for the observed effects.Results are interpreted with respect to potential effects on other ecologically important species.