MULTIOBJECTIVE REAL‐TIME RESERVOIR OPERATION WITH A NETWORK FLOW ALGORITHM1

ABSTRACT: A network flow algorithm has been developed for the optimization of real‐time operation of a multiple reservoir system. Two purposes have been considered in the operation: flood control and hydropower generation. A special network structure was developed which allows the consideration of river routing. A multiobjective formulation is utilized thus allowing generation of a non‐dominated curve. The effect of imperfect forecast on the performance of the real‐time operation model is also evaluated. An application is made to a subsystem of the Brazilian hydroelectric system, located in the Paranapanema river basin. In this case study, the model showed good performance under the largest flood of the historical records.     

Eco-friendly polyurethane foams based on castor polyol reinforced with açaí residues for building insulation

Journal of Material Cycles and Waste Management - The search for environmental sustainability has stimulated the construction sector to look for natural materials with an ecological footprint, high...     

Ecotoxicological assessment of leachates from MSWI bottom ashes

In this paper, chemical and ecotoxicological data of leachates from bottom ashes collected in different Municipal Solid Waste Incinerators (MSWI) are shown. The bottom ashes were collected in Belgium (three incinerators--samples B1 to B3), France, Germany, Italy and United Kingdom (one incinerator in each country--samples F1, D1, I1 and UK1, respectively). Both chemical and ecotoxicological characterizations of leachates were done on the framework of the European Directive 91/689/EEC and the European Council Decision 94/904/EC. This work was carried out under the European project called Valomat, which was supported by the European Commission through Brite-Euram III program. Twenty-one inorganic parameters were analyzed. The ecotoxicological assays were done under standard laboratory conditions, using the bacterium Photobacterium phosphoreum, the freshwater alga Pseudokirchneriella subcapitata, the crustacean Daphnia magna and the vegetable Lactuca sativa. Chemical data varied from sample to sample. Similar results were obtained in biological assays. The samples can be classified as ecotoxic/hazardous according to the French proposal for a Criterion and Evaluation Methods of Waste Ecotoxicity (CEMWE) and the German regulation on Hazardous Waste Classification (HWC). However, samples B1, B2, B3 and D1 comply the maximum limits for direct valorization category defined in the French Classification of Bottom Ashes based on their Polluting Potential (CBAPP). Sample B1 presented the lowest level of ecotoxicity, being considered as the most interesting to be used in the development of new materials for civil engineering works.     

Responses of a non N-limited forest plantation to the application of alkaline-stabilized dewatered dairy factory sludge

Amendment of forest soils with dewatered dairy factory sludge (DDFS), characterized by low heavy metal contents and high amounts of degradable C, can prevent the depletion of soil nutrients that results from intensive harvesting in forest plantations. However, this practice involves environmental risks when N supplies exceed the demand of plants or when the strong acidity of the soil favors the mobility of trace metals. These aspects were assessed in a young radiata pine plantation growing in a sandy, acidic, and organic N-rich soil for the 7 yr after application of a DDFS. The supply of limiting nutrients (mainly P, Mg, and Ca) provided by application of the DDFS, along with control of the ground vegetation, improved the nutritional status of the stand and led to increases in timber volume of more than 60 to 100%. Increases in soil inorganic N were observed during the first months after amendment. Data from soil incubation experiments revealed that some of the additional N was immobilized and, to a lesser extent, denitrified due to the readily available organic C content of the DDFS. Leaching and increased plant uptake of N were prevented by a combination of the latter processes and the low rate of nitrification. The strong acidity of the soil enhanced the availability of Mn and Zn to plants, although the maximum concentrations did not reach levels harmful to organisms. We conclude that although application of DDFS has positive effects on tree nutrition and growth and the environmental risks are low, repeated application may favor mobility of N and availability of heavy metals.     

Temporal and physiological influence of the absorption of nutrients and toxic elements by Eichhornia crassipes

Aquatic macrophytes are a very important subject of study due to their capacity to restore polluted aquatic environments as they need high nutrient concentrations to develop. The present study aims to determine their temporal and physiological influence on the amount of total nitrogen, gross protein, P, Cu, Ni, Co, Cd, Pb and Cr absorbed by Eichhornia crassipes (water hyacinth) in the River Apodi/Mossoró, RN, Brazil, identifying viable possibilities for the use of cultivated biomass. Results obtained from the parameters analyzed show that these substances are impacted by the temporality and physiology of Eichhornia crassipes. Leaves showed higher crude protein and macronutrients, while the content of micronutrients and toxic elements was higher in roots. It could, therefore, be utilized to improve water quality in the River Apodi/Mossoró.     

Chemical composition, sources, solubility, and transport of aerosol trace elements in a tropical region

Aerosol particle samples (PM10) were collected at urban, industrial and rural sites located in Rio de Janeiro, Brazil, between October 2008 and September 2009. Aerosol samples for each site were analyzed for total and soluble metals, water-soluble ions, carboxylic acids, and water-soluble organic carbon (WSOC). The results showed that the mean PM10 concentrations were 34 μg m(-3); 47 μg m(-3) and 71 μg m(-3) at the rural, urban and industrial sites, respectively. An increase in the average concentration of these particles due to air stagnation was observed during the period from May to September for all sites, and an increase in hospitalization for respiratory problems was also reported. On average, the anions species represented 4 to 14% of total content, while cations species corresponded to 1 to 11% and 7.5% for WSOC. The overall metal content at the industrial site was nearly the double that at the rural site. The concentrations of the studied species are influenced mainly by site location and the specific characteristics present at each site. However, higher concentrations of some species were observed on particular dates and were probably due to biomass burning and African dust events. The acid/aqueous percentiles showed that the most efficiently extracted metals from the aqueous phase were V and Ni (40%), while Al and Fe represented a lower percentage (<3%). Analysis of the aqueous fraction provides important information about the bioavailability of metals that is associated with the inflammatory process in the lungs.     

UV-irradiation and BDD-based photoelectrolysis for the treatment of halosulfuron-methyl herbicide

Environmental Science and Pollution Research - This paper reports the development of a novel photoelectrochemical (PEC) oxidation technique based on UV-C irradiation and boron-doped diamond (BDD)...     

Hepatitis A Outbreaks and Environmental Circulation of Genotype IA Strains in the São Paulo City, 2017–2018

Food and Environmental Virology - Hepatitis A virus (HAV) is the major cause of enterically transmitted infectious hepatitis. Between 2016 and 2017, the number of confirmed cases of hepatitis A...     

Towards a cleaner production in developing countries: a case study in a Chilean tannery.

A Chilean leather tanning industry (tannery) was studied in terms of input/output (I/O) analysis of beamhouse, tanyard and retanning processes. The physical-chemical characterization of 19 streams were investigated. Streams from the beamhouse process and some streams from the retanning process were found to have high organic contents ranging from 2.5 to 18.1 g COD L(-1). The pH ranged between 3.45 and 12.28. Sulphur was found in most of the streams whereas chromium was detected in two wastewaters from the tanyard and in seven streams from the retanning process. Pollution prevention opportunities were evaluated and an appropriate treatment strategy was proposed. The main emphasis was on determining waste reduction measures that can be easily implemented and are not particularly expensive. Measures for reduction at source were proposed to reduce water and chemicals consumption and wastewater pollution. A so-called S(index) strategy was used to evaluate proposals on segregation and specific treatment of the main chromium- and sulphur-containing wastewaters. It was suggested that some streams may be re-used, but it is necessary to apply anaerobic or aerobic treatment first, depending on their organic load. Solid wastes were also evaluated and a proposal for their reduction and disposal was made.