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261.
Virmond E De Sena RF Albrecht W Althoff CA Moreira RF José HJ 《Waste management (New York, N.Y.)》2012,32(10):1952-1961
In the present work, selected agroindustrial solid residues from Brazil – biosolids from meat processing wastewater treatment and mixture of sawdust with these biosolids; residues from apple and orange juice industries; sugarcane bagasse; açaí kernels (Euterpe oleracea) and rice husk – were characterised as solid fuels and an evaluation of their properties, including proximate and ultimate composition, energy content, thermal behaviour, composition and fusibility of the ashes was performed. The lower heating value of the biomasses ranged from 14.31 MJ kg?1 to 29.14 MJ kg?1, on a dry and ash free basis (daf), all presenting high volatile matter content, varying between 70.57 wt.% and 85.36 wt.% (daf) what improves the thermochemical conversion of the solids. The fouling and slagging tendency of the ashes was predicted based on the fuel ash composition and on the ash fusibility correlations proposed in the literature, which is important to the project and operation of biomass conversion systems. The potential for application of the Brazilian agroindustrial solid residues studied as alternative energy sources in thermochemical processes has been identified, especially concerning direct combustion for steam generation. 相似文献
262.
263.
Christine C. Moiling John C. Strikwerda John M. Norman Charles A. Rodgers Rick Wayne Cristine L.S. Morgan George R. Diak John R. Mecikalski 《Journal of the American Water Resources Association》2005,41(6):1289-1313
A precision scale landscape model designed for agricultural applications is described in this paper. The Precision Agricultural Landscape Modeling System (PALMS) is a combination of two process‐based models: a diffusive wave runoff model with ponding (described in detail) and a biosphere model with a crops module (briefly reviewed). Several innovations, including numerical formulations for the hydrologic properties of the soil surface with crusting, slope/tillage angle interactions, and change of roughness and detention storage with cumulative precipitation have been included. The model is compared to observations on one 1.8 ha field planted with maize and soybeans during four growing seasons, and one 24 ha field planted with maize during one growing season. Daily average soil moisture is simulated well (within 5 percent volumetric), except in extended runoff/ponding episodes. Physical processes not simulated in the model suggest possible explanations for model errors. Planned improvements for PALMS are also presented. 相似文献
264.
Ground flora trampling studies: Five years after closure 总被引:8,自引:1,他引:8
Trampling as an ecological factor is a major concern of the management of park, forest, nature preserves, and wilderness areas
as recreational resources. Of particular importance to the management concept of carrying capacity is the relative resistance
of native plant communities, to trampling and the resilience or the capacity of impacted communities to recover. This information
can be used by management to establish seasonal use limits to prevent irreversible degradation of these resources. The purpose
of this study was to follow the recolonizaton of experimental trail surfaces barren of vegetative cover and hiked at three
levels of use intensity. Results of this study indicate that soil compaction as measured by soil penetration resistance increased
progressively with use level while the total number of species, species diversity, and dominant index scores declined. A major
finding was that the greatest degree of change occurred at the first level of hiking, indicating that major floristic measures
were most affected by the least amount of hiking. Recolonization of impacted areas that received 100 trampling passes as measured
by plant cover, dominant indices, floristic dissimilarity, and species diversity was similar to areas receiving four and eight
times more trampling, despite major differences in soil penetration resistance. These data suggest limited use delivered at
one time can be as damaging as increasing levels of use delivered at over time. 相似文献
265.
Robles C Greff S Pasqualini V Garzino S Bousquet-Mélou A Fernandez C Korboulewsky N Bonin G 《Journal of environmental quality》2003,32(6):2265-2271
The aim of the present study is to assess whether certain ecophysiological responses (contents of total phenols, total proanthocyanidins, and total and simple flavonols), in the needles of Aleppo pines (Pinus halepensis Mill.) may be valid bioindicators for the assessment of the air quality. Samples were taken at five natural sites polluted by various pollutants (NO, NO2, other NOx, SO2, and O3). The results show a decrease in total phenol concentrations with levels of nitrogen oxide pollutions (significant negative correlations between the total phenol concentrations and concentrations of NO, NO2, and other NOx). Total flavonoids (total flavonols and proanthocyanidins) are useful bioindicators for ozone pollution (significant negative correlations between total proanthocyanidins and the concentrations of ozone and significant positive correlations between total flavonols and the ozone pollution). Sulfur dioxide pollution is distinguished by low concentrations in quercetin, isorhamnetin, and kaempferol (significant negative correlations between these simple flavonols and the concentrations of SO2). This work confirms the strong interest of using the phenolic compounds of Pinus halepensis as biological indicators of air quality. 相似文献
266.
Holmström Sara J. M. Riise Gunnhild Strand Line Tau Geibe Christine Van Hees Patrick A. W. Wu Qinglan Lundström Ulla S. 《Water, Air, & Soil Pollution: Focus》2003,3(4):97-120
Dissolved organic carbon (DOC) fractions and different low molecular weight organic acids (LMWOAs) were determined in soil solutions from two lime or ash treated Norway spruce sites in the south of Sweden. At Hasslöv, 3.45 t ha-1 or 8.75 t ha-1 dolomite were applied 15 years before sampling. Horröd was treated with 4.28 t ha-1 ash and 3.25 t ha-1 dolomite and sampled four years later. Propionate (7–268 M) and malonate (2–34 M) were the LMWOAsfound in the highest concentrations at Hasslöv. Two other LMWOAs dominated at Horröd, namely citrate (18–64 M)and fumarate (5–31 M). The differences in concentration of most of the determined LMWOAs at Hasslöv were significantly increased due to treatment. The LMWOAs comprised between 1.1–6.3% of the DOC at Hasslöv and 4.5–17.6% at Horröd. At Hasslöv normally 3–10% of the total acidity (TA) was due to LMWOAs and the average specific buffer capacity was 74 ± 22 mmol mol-1C.The total DOC concentration in the mor layer solution was 16 mM for the dolomite treated plots compared to 10 mM at the untreated plot. A major part of the increase in DOC at the treated plots apparently had a hydrophobic character and was of high molecular weight corresponding to 3–10 kDa. The concentration of DOC < 1 kDa in the control and treated plots was similar. 相似文献
267.
Seasonal variations of heavy metals in central Greenland snow deposited from 1991 to 1995 总被引:1,自引:0,他引:1
Barbante C Boutron C Morel C Ferrari C Jaffrezo JL Cozzi G Gaspari V Cescon P 《Journal of environmental monitoring : JEM》2003,5(2):328-335
To better assess the seasonality in the fallout of heavy metals to central Greenland, a continuous series of 68 snow samples has been collected at a remote site in the Summit area from a 2.7 m pit using ultraclean sampling procedures. This covers a continuous four year time period from spring 1991 to spring 1995. Co, Cu, Zn, Mo, Rh, Pd, Ag, Cd, Sb, Pt, Pb, Bi and U were determined using ultrasensitive inductively coupled plasma sector field mass spectrometry under clean room conditions. In addition we also determined Al by graphite furnace atomic absorption spectrometry and Na+, Ca2+, SO4(2-), MSA and oxalate by ion chromatography, species that will assist in the interpretation of the trace metal data. The data show pronounced inter- and intra-annual variations, with large differences in the amplitude of these variations for the element studied, with few clear seasonality patterns. Generally, high concentrations are observed in the spring snow layers, while much lower concentrations are typical of summer snow layers. Significant correlations are observed between Co, Cu, Zn, Ag and Sb, while Pt, Pd and Rh show no correlation with the other metals. Crustal enrichment factors show that while the crustal dust contribution is probably important for some metals for part of the year (spring), anthropogenic inputs are as important in many instances. Pronounced intra-annual variations are observed for some metals, in particular Pt. The variations observed for this metal parallel fairly closely changes in Russian Pt production, which points to emissions from smelters in the Russian Arctic as likely sources for Pt. 相似文献
268.
Nitrification is a microbial key step of the nitrogen cycle, which performs the oxidation of ammonium to nitrate, via nitrite. In aquatic environments, it mainly takes place in the sediment or is associated with suspended particles. Wastewater treatment plant (WTP) discharges in rivers may disrupt sediment nitrification: this impact is related to nitrogen inputs (mainly NH(4)(+) and organic nitrogen) but could also depend on the nitrifying bacteria inputs which have been proved to survive downstream WTP discharge points. The aim of the present study was to assess the effect of NH(4)(+) and nitrifying bacteria inputs on the two steps of nitrification in freshwater sediments.To avoid natural sites constraints and to control the main environmental parameters, we used microcosms to simulate a river receiving different types of WTP discharges. These microcosms were composed of five glass dual-walls reactors (6 l) containing sediment and continuously filled (controlled flow) with river water and WTP effluent. Two types of effluents were tested: a non-nitrified one (high NH(4)(+) input, very few nitrifying bacteria) and a nitrified one (low NH(4)(+) input, more nitrifying bacteria), at different effluent/freshwater ratios (0/100, 20/80, 40/60 and 80/20). Changes in the ammonium- and nitrite-oxidizing communities were assessed by the Most Probable Number method, and changes in potential ammonium-oxidizing activity and potential nitrite-oxidizing activity were determined by incubations with specific inhibitors (sodium chlorate and allylthiourea).In most of the cases the presence of effluent induced significant changes of the nitrifying bacteria densities and potential activities in the sediment. This effect indicates generally a loss of specific potential activity and in most of the time is significant for a high effluent/river water ratio (40% to 80%). In our experimental conditions and in the case of a large WTP discharge, the nitrifying potential in freshwater sediments could thus be significantly modified. 相似文献
269.
John H. Hartig Christine Trautrim David M. Dolan David E. Rathke 《Journal of the American Water Resources Association》1990,26(2):201-207
ABSTRACT: Ohio signed into law a detergent phosphorus ban on March 26, 1988. This law limits the elemental phosphorus content of household laundry detergents to 0.5 percent in all 35 Lake Erie counties in Ohio by 1990. Ohio's detergent phosphorus ban will help non-compliant municipal wastewater treatment plants achieve compliance with the 1 mg/L effluent phosphorus standard. By limiting the phosphorus content of household laundry detergents, Ohio will also benefit from less phosphorus entering surface waters from combined sewer overflows, communities with treatment plant bypasses, and riparian homes with septic tanks. This is important because most of the phosphorus in laundry detergents is in the bioavailable form and Ohio's Lake Erie shoreline is particularly sensitive to Cladophora problems. When viewed in conjunction with reduced chemical costs for phosphorus removal and savings in sludge disposal costs, Ohio's detergent phosphorus ban is a pragmatic component of an international phosphorus management strategy to protect the Great Lakes. 相似文献
270.
In Vienna during more than 10 years of research work a special traffic behaviour observation method has been developed, evaluated and applied by Risser et al. in the frame of many different traffic safety projects. Car drivers are accompanied by two observers who register not only errors in behaviour of drivers but also their communication and interaction with other road users. Malfunction of communication and interaction are judged as main sources for problems for danger in traffic. For example, if they lead to a bad traffic climate fealings of discomfort, anger and frustration will prevent cooperative actions of road users. Being able to recognize such negative or dangerous interaction patterns in time it seems to be easier to protect road users — most often the ‘unprotected’ ones — from getting involved in accidents. This contribution gives an impression about theory and practice of the observation method and shows results of different studies, where the method called ‘Wiener Fahrprobe’ has been applied. Furthermore it will show how the method and its results can be used in the frame of the European traffic (safety) research projects ‘PROMETHEUS’ and ‘DRIVE’. Till now no accident data exist in respect to new RTI systems. Therefore it seems to be important to have a sophisticated social-psychological method for testing the behaviour and interaction of road users in connection with these systems. This is a necessary prediction for deciding whether the systems are socially compatible or not. 相似文献