762 resultados para Sewage lagoons -- Tasmania
Resumo:
Ocean acidification (OA) is the reduction in seawater pH due to the absorption of human-released CO2 by the world's oceans. The average surface oceanic pH is predicted to decline by 0.4 units by 2100. However, kelp metabolically modifies seawater pH via photosynthesis and respiration in some temperate coastal systems, resulting in daily pH fluctuations of up to ±0.45 units. It is unknown how these fluctuations in pH influence the growth and physiology of the kelp, or how this might change with OA. In laboratory experiments that mimicked the most extreme pH fluctuations measured within beds of the canopy-forming kelp Ecklonia radiata in Tasmania, the growth and photosynthetic rates of juvenile E. radiata were greater under fluctuating pH (8.4 in the day, 7.8 at night) than in static pH treatments (8.4, 8.1, 7.8). However, pH fluctuations had no effect on growth rates and a negative effect on photosynthesis when the mean pH of each treatment was reduced by 0.3 units. Currently, pH fluctuations have a positive effect on E. radiata but this effect could be reversed in the future under OA, which is likely to impact the future ecological dynamics and productivity of habitats dominated by E. radiata.
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Stabilization ponds are biological treatment systems in that stabilization of organic matter is performed by the bacterial oxidation and / or reduction of photosynthetic algae. This study aimed to monitor and evaluate the efficiency of stabilization ponds in the Rio Grande do Norte State. Collections were made of the treated effluent, made directly in the output boxes of facultative lagoons and maturation (M1 and M2) and raw sewage (EB) that arrived at the stations. The variables analyzed were: pH, temperature, dissolved oxygen, total suspended solids, chlorophyll "a", apparent color, total phosphorus, organic nitrogen, ammonia nitrogen, Kjeldahl nitrogen, turbidity, cyanobacteria density and concentrations of microcystin. Variance analysis (ANOVA one way) observing the premises using the Tukey test, so as to check differences between treatments. The evaluate the stations found to COD removals in the bands of 48,8% (Pipa) to 75,8% (Caiçara Rio do Vento) and 57,5% (Pipa) to 83,0% (Santo Antônio), respectively. The mean concentrations of cyanobacteria varied from LFs density of 62,545 cels.mL-1 (Pedro Velho Roça) cels.mL-1 to 2,669,048 (Ponta Negra), while the final effluent showed range between 9,072 Cels.mL- 1 (Pedro Velho Roça) to 1,899,981 cels.mL-1 (Macau – Ilha de Santana) and the average concentrations of microcystin the final effluent ranged from 0.02 μg.L-1 (Ponta Negra) to 0.15 μg.L-1 (Macau – Ilha de Santana) at the studied the stations.
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The South America southern coast exhibits many outcrops with abundant shell beds, from the Pleistocene through the Recent. How much biological information is preserved within these shell beds? Or, what is the actual probability a living community has to leave a fossil record corresponding to these shell deposits? Although ecological and biogeographical aspects might had been pointed, considering these temporal scales, up to the moment there is no taphonomically-oriented studies available. Quantitative comparisons between living (LAs), death (DAs) and fossil assemblages (FAs) are important not only in strictly taphonomic studies, but have grown a leading tool for conservation paleobiology analysis. Comparing LAs, DAs and FAs from estuaries and lagoons in the Rio Grande do Sul Coastal Plain makes possible to quantitatively understand the nature and quantity of biological information preserved in fossil associations in Holocene lagoon facies. As already noted by several authors, spatial scale parts the analysis, but we detected that the FAs refl ects live ones, rather than dead ones, as previously not realized. The results herein obtained illustrates that species present in DA are not as good preserved in recent (Holocene) fossil record as originally thought. Strictly lagoon species are most prone to leave fossil record. The authors consider that the fi delity pattern here observed for estuarine mollusks to be driven by (i) high temporal and spatial variability in the LAs, (ii) spatial mixing in the DA and (iii) differential preservation of shells, due to long residence times in the taphonomically active zone.
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This picture shows the men of the Detroit Dredging Company hand digging lagoons for owner George A. Boeckling at Cedar Point. The lagoon network would be used for transportation so that visitors could reach the boat docks at the Hotel Breakers. They also made it possible to carry coal to the new electric power station. Visitors could also enjoy traveling the lagoons by themselves.
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Conservation of the seven lagoons of the Palavas complex (southern France) has been severely impaired by nutrient over-enrichment during at least four decades. The effluents of the Montpellier wastewater treatment plant (WWTP) represented the main nutrient input. To improve the water quality of these lagoons, this WWTP was renovated and upgraded and, since the end of 2005, its effluents have been discharged 11 km offshore into the Mediterranean (total investment €150 M). Possibilities of ecosystem restoration as part of a conservation programme were explored by a focus group of experts. Their tasks were: (i) to evaluate the impact of the reduction of the nutrient input; (ii) if necessary, to design additional measures for an active restoration programme; and (iii) to predict ecosystem trajectories for the different cases. Extension of Magnoliophyta meadows can be taken as a proxy for ecosystem restoration as they favour the increase of several fish (seahorse) and bird (ducks, swans, herons) species, albeit they represent a trade-off for greater flamingos. Additional measures for active ecosystem restoration were only recommended for the most impaired lagoon Méjean, while the least impaired lagoon Ingril is already on a trajectory of spontaneous recovery. A multiple contingent valuation considering four different management options for the Méjean lagoon was used in a pilot study based on face-to-face interviews with 159 respondents. Three levels of ecosystem restoration were expressed in terms of recovery of Magnoliophyta meadows, including their impact on emblematic fish and avifauna. These were combined with different options for access (status quo, increasing access, increasing access with measures to reduce disturbance). The results show a willingness of local populations to pay per year about €25 for the highest level of ecological restoration, while they were only willing to allocate about €5 for additional footpaths and hides.
Resumo:
Rotavirus double-stranded RNA was detected directly in sewage treatment plant samples over a 1-year period by reverse transcription followed by PCR amplification of the VP7 gene and Southern blot hybridization. The presence of naturally occurring rotaviruses was demonstrated in 42% of raw sewage samples and in 67% of treated effluent samples, Amplified viral sequences were analyzed bg restriction enzymes. Ten different restriction profiles were characterized, most of which were found in treated effluent samples. A mixture of restriction profiles was observed in 75% of contaminated effluent samples, The profiles were compared with those obtained from human rotavirus isolates involved in infections in children from the same area (six different profiles were detected), Five identical viral sequences were detected in both environmental and clinical samples, Restriction profiles sere also compared io profiles from known genomic sequences of human and animal viruses. Both human and animal origins of rotavirus contamination of water seemed likely.
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This study shows a possibility of using municipal sewage sludge after thermal treatment in the production of a filtering material to water treatment. Due to the fast urbanization and implementation of high standards for effluent in many countries in recent years, the sewage sludge is being produced in an ever increasing amount. Therefore, the use of sludge is a suitable solution for the expected large quantity of sludge. Dehydration of sludge was performed by controlled heating at temperatures of 1100 degrees C, 850 degrees C, 650 degrees C, 350 degrees C for 3 hours. After thermal treatment the sludge was characterized by X-ray fluorescence, TG/DTG/DTA, residue solubilization and residue lixiviation tests. The aim of the present work was to observe, thought the characterization techniques, if the treated sewage sludge is or not adequate to be used as filter material to water treatment. It will be verified which treatment temperature of the sludge offer possibility to its use in water treatment without carrying pollutants in concentrations out of the standards.
Resumo:
The processing of industry and domestic effluents in wastewater treatment plants reduces the amount of polluted material and forms reusable water and dehydrated sludge. the generation of hazardous municipal sludge can be decreased, as well as the impact on surface and underground water and the risk to human health. The aim this study is to verify the possibility to use sintered sewage sludge as support material after thermal treatment in the production of a filtering material to water supply systems. After thermal treatment the sewage sludge ash was characterized by X-ray fluorescence (XRF), leaching test and water solubilization. Dehydration of sludge was performed by controlled heating at temperatures of 180 degrees C, 350 degrees C, 600 degrees C, 850 degrees C and 1000 degrees C for 3 hours.
Resumo:
The submarine sewage outfall of Santos (SSOS) is situated in the Santos Bay (São Paulo, Brazil) and is potentially a significant source of contaminants to the adjacent marine ecosystem. The present study aimed to assess the influence of SSOS on the sediment toxicity and contamination at Santos Bay. At the disposal site, sediments tended to be finer, organically richer and exhibited higher levels of surfactants and metals, sometimes exceeding the Threshold Effect Level values. The SSOS influence was more evident toward the East, where the sediments exhibited higher levels of TOC, total S and metals during the summer 2000 sampling campaign. Sediment toxicity to amphipods was consistently detected in four of the five stations studied. Amphipod survival tended to correlate negatively to Hg, total N and % mud. This work provides evidence that the SSOS discharge affects the quality of sediments from Santos Bay, and that control procedures are warranted. (c) 2005 Elsevier Ltd. All rights reserved.
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2009
Resumo:
The need for solutions to minimize the negative environmental impacts of anthropogenic activities Fhas increased. Sewage sludge is composed of predominantly organic matter and can be used to improve soil characteristics, such as fertility. Therefore, its application in agriculture is an adequate alternative for its final disposal. However, there is a lack of information on its long-term effects on soil changes in tropical areas. Thus, the objectives of this study were to determine (i) the effect of sewage sludge application on heavy metal build-up in soil and maize grains and leaves, and (ii) the effects of soil amendment with sewage sludge on the chemical properties of a Brazilian oxisol. Besides the increasing levels of Zn, Cu, Ni, and Cr, amending soil with sewage sludge also alters the distribution of these metals by increasing the mobile Phases, which correlated significantly with the increase in metal extraction with two single extractants, Mehlich 1 and DTPA (Diethylene triamine pentaacetic acid). The levels of Fe, Mn, Zn, and Cu in maize grains and leaves increased with the type and rate of sewage sludge application. Nevertheless, metal build-up in soil and plants was within the allowed limits. Significant differences were also found in soil characteristics like humic fractionation with the applied sewage doses. The data obtained does not indicate any expressive drawbacks in the use of sewage sludge as a soil amendment, as the heavy metal concentrations observed are unlikely to cause any environmental or health problems, even overestimated loadings, and are in accordance with the Brazilian regulations on farming land biosolid disposal.
Resumo:
2009