Study of the organic matter evolution during municipal solid waste composting aimed at identifying suitable parameters for the evaluation of compost maturity

In this work the composting process of municipal solid wastes was studied in order to characterize the transformations of organic matter, particularly humic acid (HA). A composting process, lasting three months, was monitored by chemical methods; the following parameters were measured: water-soluble carbon concentration (WSC) and humic substances content (humic and fulvic acid (FA)). The effects of humification on the molecular structure of humic acid (HA) were also evaluated by Fourier transform infrared (FT-IR) and (13)C NMR spectroscopy. WSC concentration rapidly increased reaching a maximum at day-14 of the composting process and then declined. The humic and fulvic acid content (HA and FA, respectively) slightly increased during the process. The FT-IR and (13)C NMR spectra of HA indicate a high rate of change in structure during composting. The groups containing aromatic and carboxylic C increased, while polysaccharides and other aliphatic structures degraded during composting, resulting in HA structures of higher aromaticity. Therefore, spectrometric measurements could provide information significantly correlated to conventional chemical parameters of compost maturity.     

A stochastic model for the use of a country park

The subject of this theoretical study is a country park with a very delicate natural environment, located near large urban areas, as a result of which it receives a heavy inflow of visitors.The problem is that of determining the best organization of the park to achieve a distribution of visitors which is compatible with the protection of the natural environment. Therefore a mathematical model is sought which describes the distribution of visitors in relation to the various zones within the park.In this paper the mathematical model and its subsequent calibration are described.     

Laboratory-numerical studies of stratified spin-up flows

The stability of stratified rotating flows is investigated by means of laboratory experiments and numerical simulations in axisymmetric cylindrical and annular containers with both horizontal and sloping bottoms. The baroclinic current is initiated via incremental spin-up/down of a linearly stratified fluid by an abrupt change in the rotation rate of the system. Particular attention is given to the non-linear flow regime (finite Rossby numbers). It is found that axisymmetric spin-up current loses its azimuthal symmetry when the Burger number drops below unity, and breaks into a system of large-scale cyclonic and anticyclonic vortices with predominantly vertical axis of rotation. Eddies always develop at the density fronts formed by the corner regions adjacent to the sidewalls of the container. It is shown that the stability of the spin-up flow is largely affected by the bottom slope and the structure of the bottom boundary layer.     

Optimal conditions for chlorothalonil and dissolved organic carbon in horizontal subsurface flow constructed wetlands

The most efficient system of horizontal subsurface flow constructed wetlands (HSSFCW) for removing dissolved organic carbon (DOC) in the presence of chlorothalonil pesticide (CLT) present in synthetic domestic wastewater was determined using the macrophyte Phragmites australis. Two concentrations of CLT (85 and 385 μg L^?1) and one concentration of glucose (20 mg L^?1) were evaluated in four pilot scale horizontal surface flow constructed wetlands coupled with two sizes of silica gravel, igneous gravel, fine chalky gravel (3.18–6.35 mm), coarse gravel (12.70–25.40 mm) and two water surface heights (20 and 40 cm). For a month, wetlands were acclimated with domestic wastewater. Some groups of bacteria were also identified in the biofilm attached to the gravel. In each treatment periodic samplings were conducted in the influent and effluent. Chlorothalonil was quantified by gas chromatography (GC-ECD m), DOC by an organic carbon analyzer and bacterial groups using conventional microbiology in accordance with Standard Methods. The largest removals of DOC (85.82%–85.31%) were found when using fine gravel (3.18–6.35 mm) and the lower layer of water (20 cm). The bacterial groups quantified in the biofilm were total heterotrophic, revivable heterotrophic, Pseudomonas and total coliforms. The results of this study indicate that fine grain gravel (3.18–6.35 mm) and both water levels (20 to 40 cm) can be used in the removal of organic matter and for the treatment of agricultural effluents contaminated with organo-chloride pesticides like CLT in HSSFCW.     

Blood markers among residents from a coal mining area

Environmental Science and Pollution Research - Coal extraction and processing generate environmental contamination, which has several negative impacts on human health. Hematological and biochemical...     

Carnauba (Copernicia prunifera) palm tree biomass as adsorbent for Pb(II) and Cd(II) from water medium

Environmental Science and Pollution Research - Plant-based biomass (CFB (carnauba fruit biomass)) obtained from the fruit exocarp of the species Copernicia prunifera (Mill.) H.E. Moore (carnauba)...     

Geoprocessing applied to the assessment of environmental noise: a case study in the city of Sorocaba, S?o Paulo, Brazil

Noise mapping has been used as an instrument for assessment of environmental noise, helping to support decision making on urban planning. In Brazil, urban noise is not yet recognized as a major environmental problem by the government. Besides, cities that have databases to drive acoustic simulations, making use of advanced noise mapping systems, are rare. This study sought an alternative method of noise mapping through the use of geoprocessing, which is feasible for the Brazilian reality and for other developing countries. The area chosen for the study was the central zone of the city of Sorocaba, located in São Paulo State, Brazil. The proposed method was effective in the spatial evaluation of equivalent sound pressure level. The results showed an urban area with high noise levels that exceed the legal standard, posing a threat to the welfare of the population.     

Poverty and the Deterioration of Natural Soil Capital in the Peruvian Altiplano

The Peruvian altiplano is a marginal agricultural region with limited infrastructure, climate constraints, and high levels of poverty. Data were collected from 265 farms in four different agricultural regions, and data from three of those regions are analyzed here. Regressions were run with soil nutrient loss, soil depth loss, and yield loss over the past 20 years, as perceived by farmers. Location, topographical and management factors were considered. Additional regressions were run to examine the determinants of two agricultural management practices which were found to affect soil quality, namely fallowing and ploughing vertical furrows. Use of traditional fallowing (aynoca) was associated with helping to preserve soil quality, and was practiced by households with more education, with higher non-farm income, and in villages which had benefitted from natural resource development projects. Vertical furrowing similarly was associated with helping preserve soil quality, and was practiced by households with fewer unmet basic needs. These results have implications for the agricultural and development strategies to be followed in the region.