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11.
R. Maurício L. Amaral P. Santos Coelho F. Santana 《Environmental monitoring and assessment》2013,185(12):10085-10089
Biofilms are present in several areas and are studied in microbiology, medical sciences, biology and, of course, sanitary engineering. Biofilms are used for the treatment of municipal wastewater, and their application was even before the invention of the activated sludge process. The main objective of this work was to develop a simple, fast and low-cost technique to evaluate the nature of the first decay in the concentration of an organic compound in the presence of a solid material. Though simple, the technique developed has allowed the clarification of whether the initial concentration decay is due to adsorption to the support material or a result of biodegradation. The results show that, with two different support materials, adsorption does not take place, and the biodegradation processes are responsible for the first decay in the organic concentration. The technique used offers a fast and low-cost way of studying the existence of adsorption. Two feed concentration solutions and two different support materials were used. 相似文献
12.
Edumar Ramos Cabral Coelho Lorena Frasson Loureiro Miguel Angelo Schettino Jr. Jair Carlos Checon de Freitas 《Journal of environmental science and health. Part. B》2020,55(4):361-375
AbstractActivated carbons are well-known porous materials as an effective adsorbent used for the removal of emerging contaminants, such as herbicides, which are increasingly present in water bodies. Most water treatment plants, specially in Brazil, are unable to completely remove such contaminants by the conventional process and advanced treatment using activated carbons is required. The aim of this paper was to verify the influence of the activated carbons granulometry and specific surface area on the 2,4-dichlorophenoxyacetic acid (2,4-D) herbicide removal efficiency using distilled-deionized water and filtered water collected from a conventional Water Treatment Plant. Commercial activated carbons samples used in this work were obtained from two different manufacturers. Activated carbons were analyzed by the specific surface area, pore size and volume distribution, nuclear magnetic resonance, infrared and x-ray spectroscopy, moisture, volatile matter and ash contents. Batch adsorption isotherms experiments were used and performed by Langmuir and Freundlich models. Granular and powdered activated carbons removed over 99% of 2,4-D in distilled water and near to 99% using filtered water. The activated carbons evaluated in this work presented high performance and played a key role in water treatment by removing 2,4-D herbicide, ensuring the protection of human health and the ecosystem. 相似文献
13.
F. Veloso-Gomes F. Taveira-Pinto Luciana das Neves Joaquim Pais Barbosa Carlos Coelho 《Journal of Coastal Conservation》2004,10(1):43-52
The entire northwestern coast of Portugal is undergoing severe erosion and there are several areas at high risk of erosion.
Commonly considered as a problem—because it jeopardizes human development along the coast—erosion is indeed a natural process
of sediment redistribution. This paper presents a brief analysis of erosion driving forces and the subsequent state of vulnerability
that coastal segments between the mouth of the River Douro and Cape Mondego are facing. The paper also discusses erosion risk
levels, low or high, and the subsequent questions whether there are populations, economical assets or natural habitats at
risk and/or areas prone to coastal flooding. Main challenges and future trends along the study area are identified in the
light of understanding the underlying causes of conflicts and what realistically can be achieved given the morphodynamics
and hydrodynamic processes, human development established along this coastal segment and the existing policies. 相似文献
14.
Photoreactivity of humic substances: relationship between fluorescence and singlet oxygen production 总被引:1,自引:0,他引:1
Christian Coelho Ghislain Guyot Alexandra ter Halle Luciano Cavani Claudio Ciavatta Claire Richard 《Environmental Chemistry Letters》2011,9(3):447-451
Humic substances are natural compounds abundantly present in the environment. They play a significant role in the natural
attenuation of pollution in surface water due to their capacity to generate reactive species upon solar light excitation.
Finding physico chemical parameters related to this property would be of a great help in the prediction studies of the organic
pollutants fate. In this work, we investigated relationships between the ability of the humic substances to produce singlet
oxygen and their fluorescence properties. For this, a series of sixteen humic acids, fulvic acids, and water-extractable organic
matter from soils were studied. The steady-state singlet oxygen concentrations in the irradiated humic substances solutions
were measured by monitoring the loss of furfuryl alcohol added as a singlet oxygen scavenger. The emission spectra of the
sixteen samples were also recorded. Values of the steady-state singlet oxygen concentrations and the emission intensities
showed significant variations among the humic samples and a parallel increase. Thus, here we demonstrate that the rate of
singlet oxygen production and the emission intensity of the humic samples are correlated, the best correlation being obtained
for emission wavelengths between 500 and 580 nm. This correlation which was never reported until now can be used to estimate
the singlet oxygen-production capacity of the humic substances based on their fluorescent properties. 相似文献
15.
The quality of water draining fields fertilized with liquid swine (Sus scrofa) manure (LSM) sidedressed into standing corn (Zea mays L.) at rates ranging from 0 to 94 m(3) ha(-1), either topdressed (TD) onto the surface, or injected (INJ) into the soil once annually for each of three consecutive years was evaluated. Liquid swine manure application rate was a critical driver of preferential flow of LSM to tile as detected by turbidity, concentrations of NH(4)(+)-N, dissolved reactive phosphorus (DRP), and the presence of enteric bacteria (Escherichia coli). Contaminant movement to drains occurred immediately after 75 and 94 m(3) LSM ha(-1) were injected (e.g., 2.5 mg DRP L(-1), 3-yr average). With injection of 56 m(3) ha(-1) or less, drainage water was not turbid and concentrations of NH(4)(+)-N, DRP, and enteric bacteria were dramatically lower than with the higher rates, even when tiles flowed freely during manure application. Application method also affected tile water quality. With TD applications (37 and 56 m(3) ha(-1)), nutrients and bacteria did not move to tiles at the time of application, but with rains that fell within 3 d after application, concentrations increased (e.g., 0.1 mg DRP L(-1)), although less than with INJ. Overall, sidedress injection rates that supplied adequate crop nutrients did not compromise drainage water quality. 相似文献
16.
Part I of this study deals with the primary energy consumption and CO2eq emissions of a 350 tonnes/h construction and demolition waste (CDW) recycling facility, taking into account incorporated, operation and transportation impacts. It concludes that the generated impacts are mostly concentrated in operation and transportation, and that the impacts prevented through material recycling can be up to one order of magnitude greater than those generated.However, the conditions considered for the plant’s operation and related transportation system may, and very likely will, vary in the near future, which will affect its environmental performance. This performance is particularly affected by the plant’s installed capacity, transportation fuel and input CDW mass. In spite of the variations in overall primary energy and CO2eq balances, the prevented impacts are always higher than the generated impacts, at least by a factor of three and maybe even as high as 16 times in particular conditions. The analysis indicates environmental performance for variations in single parameters, except for the plant’s capacity, which was considered to vary simultaneously with all the others. Extreme best and worst scenarios were also generated to fit the results into extreme limits. 相似文献
17.
Coelho Paula Nunes Paes Thécia Alfenas Silva Valente Maia-Barbosa Paulina Maria dos Santos-Wisniewski Maria José 《Environmental science and pollution research international》2021,28(24):30887-30897
Environmental Science and Pollution Research - Here, we describe the abundance and composition of the dormant-stage banks of cladocerans and rotifers at two locations in a tropical reservoir... 相似文献
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19.
Eugenio Erika de Queiros Campisano Ivone Sampaio Pereira de Castro Aline Machado Coelho Maria Alice Zarur Langone Marta Antunes Pereira 《Journal of Polymers and the Environment》2022,30(4):1627-1637
Journal of Polymers and the Environment - The search for a straightforward technology for post-consumer poly(ethylene terephthalate) (PC-PET) degradation is essential to develop a circular economy.... 相似文献
20.
Maria João Gonçalves Ana Catarina Calado Santos Carlos Fernando Dias Rodrigues Pedro Coelho André Nuno Costa António Jorge Guiomar 《毒物与环境化学》2013,95(6):1202-1211
In the 1920s, Otto Warburg reported a striking metabolic shift in solid tumors: contrary to their normal counter parts, which exhibited a nearly pure respiratory metabolism, where cancer cells relied strongly on lactic fermentation for energy production, even in the presence of ample oxygen. This metabolic shift, later named the Warburg effect, is now viewed as a nearly universal cancer phenotype. To investigate whether it is operating in hexavalent chromium (Cr(VI))-induced carcinogenesis, PC-12 cells were exposed to low Cr(VI) concentrations and effects determined on the rates of glucose uptake, lactate production and oxygen consumption, critical indicators of the type of energy metabolism adopted by the cells. Further, the influence on the cells’ energy charge, an important parameter in the evaluation of the cellular physiological state was assessed. In the presence of ample oxygen, concentration-dependent, statistically significant decreases in the energy charge were detected, which were accompanied by an increased glucose uptake rate. This enhanced uptake may constitute the first step in a compensatory mechanism aimed at counteracting the decrease in energy charge. Although these changes may be too small to exert an impact in the cellular functions, they may provide insight into the initial steps of Cr(VI)-induced carcinogenesis. 相似文献