Study of stillage biodegradation by respirometry in sandy and clay soils

The stillage, which is a liquid residue from the distillation of the sugarcane ethanolic fermentation, contains organic matter and can be a big source of pollution when it is discarded in the wrong way. Its application as fertilizer has been extended, which is reason to cause concerns regarding the environment. The aim of this work was to evaluate and quantify the biodegradation of stillage in sandy and clay soils, besides verifying the efficiency of the Embiotic Line®inoculum as an accelerator of the biodegradation. Bartha and Pramer respirometric technique was used to determine the production of CO2 during the 50 days of the biodegradation process, and the quantification of the initial and final microorganisms was also conducted. Results were analyzed using the Friedman statistical test. Clay soils were significantly better on stillage decomposition when compared to sandy soils (p=0.0153). Clay soils presented greater efficiency in stillage biodegradation, with higher field capacity, better water, organic matter and microbial retention. Regarding the use of the embiotic line, the experiment has shown this product does not interfere positively in the stillage biodegradation for both soils, possibly needing adjustments in its composition.

LIVER DAMAGES AND NUCLEAR ABNORMALITIES IN ERYTHROCYTES OF Atherinella brasiliensis (ACTYNOPTERIGII, ATHERINOPSIDADE) FROM TWO BEACHES IN SOUTHEAST OF BRAZIL

There are few environmental studies using biomarkers for the species Atherinella brasiliensis in Brazil. In the present work, the presence of hepatic histopathological lesions and nuclear abnormalities in erythrocytes were investigated in A. brasiliensis from Lamberto, a beach under influence of domestic wastes and marine activities. For comparison, fish were also sampled in Puruba, a non-polluted beach, located in the northeastern of Sao Paulo State. The frequency of lesions found in liver was in higher numbers in individuals from Lamberto than Puruba beach. The most critical injuries observed in A. brasiliensis were the presence of necrotic areas, leucocytes infiltration and piknotic nucleus. A high occurrence of cells with vacuolization was also observed. The hepatic lesion index of the fish from Lamberto beach showed significant high values (I(org)=13) when compared with fish from Puruba beach (I(org)=7) suggesting the influence of the several human activities in the studied site. Notched and blebed nucleous were observed in this study, and significant differences were found between the studied sites. However, these differences did not reflect the total nuclear alterations.

Morphodynamics of structurally controlled headland-bay beaches in southeastern Brazil: A review

This paper presents a comprehensive review on the interaction between hydrodynamic processes, beach morphology and sedimentology at large scale coastal behaviour along the coastline of Santa Catarina, between Laguna and Sao Francisco Island, a microtidal east coast swell environment with headland and bay geomorphologies. The parabolic bay shape equation has proven to be a convenient and practical tool for studying the stability of the headland-bay beaches, tombolos, and salients in Santa Catarina. The beaches exhibit different patterns of sediment removal as a function of the degree of beach curvature. In highly curved beaches, there is a well-developed shadow zone and a range of morphodynamic conditions, from a sheltered low-energy beach adjacent to the downdrift headland to a high-energy exposed beach on the straight end of the headland-bay beach. The less curved beaches instead, tend to show more uniform behaviour since they are directly exposed to incident waves. There is no obvious relationship between average wave height and mean grain size, showing the importance of sediment source to characterize the sedimentary distribution patterns in the study area. The analysis of beaches showed that beach morphodynamics and sequence profiles for a bay-headland coast in a microtidal east coast environment is a function of geological inheritance (e.g., distance between headlands and orientation, nearshore and inner shelf morphology, coastal plain morphology, and sediment source), and hydrodynamic factors (wave conditions, oceanic wave exposure and relative tidal range). (C) 2009 Elsevier B.V. All rights reserved.

Microbiological quality assessment of sand and water from three selected beaches of South Coast, Sao Paulo State, Brazil

This study aimed to assess the sanitary quality of water, and wet and dry sand from three beaches located in the South Coast region of Sao Paulo State, Brazil, selected taking into account the frequency of tourists and the water quality (good, fair and poor). Thirty-six water samples each of wet and dry sand and seawater were collected monthly over a period of one year and analyzed for fecal indicator bacteria (FIB: thermotolerant coliforms, Escherichia coli, and enterococci), presumptive Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans and dermatophytes. The results revealed FIB concentrations more elevated in dry sand followed by wet sand and water. P. aeruginosa and presumptive S. aureus were detected with a similar frequency in water and sand samples, but maximum concentrations and geometric means were higher in dry sand. C. albicans was detected only in water samples whereas the dermatophyte Microsporum sp. was isolated exclusively from dry and wet sand samples. This evaluation showed also that the environment had a significant influence on P. aeruginosa but not on presumptive S. aureus concentrations. According to threshold values proposed in the literature for E. coli and enterococci dry sand densities, none of the beaches would be considered of sufficient quality for recreational activities.

Problemática ambiental en la isla de La Graciosa: ¿Hay déficit de arena actual en sistemas playa-duna?

[ES] La isla La Graciosa está situada al noroeste de Lanzarote y tiene una extensión de 27,05 km2. Se trata de un área que presenta un alto valor ecológico pues está protegida a través de diferentes figuras tales como: Parque Natural y Reserva Marina del Archipiélago Chinijo, Reserva de la Biosfera de Lanzarote, Zona de Especial Protección de aves (ZEPA) y Zona de Especial Conservación (ZEC), entre otras. En la isla hay varios sistemas playa-duna tanto en la mitad nororiental de la isla (Las Conchas, Lambra y El Jablillo) como en su parte meridional (Barranco de Los Conejos, Las Caletas, El Salado y Francesa). Algunas de las playas muestran evidencias de un déficit sedimentario pues tienen una reducida o nula entrada de sedimentos arenosos al sistema y/o muestran procesos erosivos que hacen aparecer el substrato rocoso. Además, se observa en el interior de la isla la estabilización de los mantos eólicos por la vegetación. Estos ambientes eólicos costeros son esenciales, tanto para la preservación de los ecosistemas protegidos, como para la actividad turística insular. En este contexto se están desarrollando investigaciones multidisciplinares para elaborar un diagnóstico científico de esta problemática ambiental, determinando si las causas de este déficit sedimentario son naturales o antrópicas, y proponer soluciones al respecto.

A pocket beach that reaches equilibrium after becoming disconnected from a large system of beaches. Playa Barca (Fuerteventura)

[EN] Playa Barca is a 370 m long beach located within the system of the Leeward beaches on the Jandía peninsula, Fuerteventura. This system of beaches represents one of the major sources of economic income to the island, both because of its natural landscape that attract a specific type of tourism, and because of its particular climate conditions that make these beaches ideal for practicing wind-water sports. Nevertheless, in the past decades, this area has suffered from a significant and worrying coastline retreat. In order to look for an explanation to this retreat, five topographic surveys were carried out in October 1999, February 2001, February 2002, February 2003 and February 2013 to track the beach behavior in the last 15 years. A total station Topcon GTS-303D was used for this purpose. Surveys were carried out during low spring tides, so that the outer limit was the furthest possible depending on wave conditions. The inner limit covered part of the dunes in the backshore. From these topographic data both coastline changes and the sedimentary balance have been obtained.

Centrifuge Modeling of Sandy Slopes

Slope failure occurs in many areas throughout the world and it becomes an important problem when it interferes with human activity, in which disasters provoke loss of life and property damage. In this research we investigate the slope failure through the centrifuge modeling, where a reduced-scale model, N times smaller than the full-scale (prototype), is used whereas the acceleration is increased by N times (compared with the gravity acceleration) to preserve the stress and the strain behavior. The aims of this research “Centrifuge modeling of sandy slopes” are in extreme synthesis: 1) test the reliability of the centrifuge modeling as a tool to investigate the behavior of a sandy slope failure; 2) understand how the failure mechanism is affected by changing the slope angle and obtain useful information for the design. In order to achieve this scope we arranged the work as follows: Chapter one: centrifuge modeling of slope failure. In this chapter we provide a general view about the context in which we are working on. Basically we explain what is a slope failure, how it happens and which are the tools available to investigate this phenomenon. Afterwards we introduce the technology used to study this topic, that is the geotechnical centrifuge. Chapter two: testing apparatus. In the first section of this chapter we describe all the procedures and facilities used to perform a test in the centrifuge. Then we explain the characteristics of the soil (Nevada sand), like the dry unit weight, water content, relative density, and its strength parameters (c,φ), which have been calculated in laboratory through the triaxial test. Chapter three: centrifuge tests. In this part of the document are presented all the results from the tests done in centrifuge. When we talk about results we refer to the acceleration at failure for each model tested and its failure surface. In our case study we tested models with the same soil and geometric characteristics but different angles. The angles tested in this research were: 60°, 75° and 90°. Chapter four: slope stability analysis. We introduce the features and the concept of the software: ReSSA (2.0). This software allows us to calculate the theoretical failure surfaces of the prototypes. Then we show in this section the comparisons between the experimental failure surfaces of the prototype, traced in the laboratory, and the one calculated by the software. Chapter five: conclusion. The conclusion of the research presents the results obtained in relation to the two main aims, mentioned above.

Geotechnical characterization of mixed sandy and silty soils using piezocone tests: Analysis of partial drainage phenomena and rate effects on the experimental soil response

The cone penetration test (CPT), together with its recent variation (CPTU), has become the most widely used in-situ testing technique for soil profiling and geotechnical characterization. The knowledge gained over the last decades on the interpretation procedures in sands and clays is certainly wide, whilst very few contributions can be found as regards the analysis of CPT(u) data in intermediate soils. Indeed, it is widely accepted that at the standard rate of penetration (v = 20 mm/s), drained penetration occurs in sands while undrained penetration occurs in clays. However, a problem arise when the available interpretation approaches are applied to cone measurements in silts, sandy silts, silty or clayey sands, since such intermediate geomaterials are often characterized by permeability values within the range in which partial drainage is very likely to occur. Hence, the application of the available and well-established interpretation procedures, developed for ‘standard’ clays and sands, may result in invalid estimates of soil parameters. This study aims at providing a better understanding on the interpretation of CPTU data in natural sand and silt mixtures, by taking into account two main aspects, as specified below: 1)Investigating the effect of penetration rate on piezocone measurements, with the aim of identifying drainage conditions when cone penetration is performed at a standard rate. This part of the thesis has been carried out with reference to a specific CPTU database recently collected in a liquefaction-prone area (Emilia-Romagna Region, Italy). 2)Providing a better insight into the interpretation of piezocone tests in the widely studied silty sediments of the Venetian lagoon (Italy). Research has focused on the calibration and verification of some site-specific correlations, with special reference to the estimate of compressibility parameters for the assessment of long-term settlements of the Venetian coastal defences.

Dilution of non-reactive tracers in variably saturated sandy structures

Based on a dye tracer experiment in a sand tank we addressed the problem of local dispersion of conservative tracers in the unsaturated zone. The sand bedding was designed to have a defined spatial heterogeneity with a strong anisotropy. We estimated the parameters that characterize the local dispersion and dilution from concentration maps of a high spatial and temporal resolution obtained by image analysis. The plume spreading and mixing behavior was quantified on the basis of the coefficient of variation of the concentration and of the dilution index. The heterogeneous structure modified the flow pattern depending on water saturation. The shape of the tracer plumes revealed the structural signature of the sand bedding at low saturation only. In this case pronounced preferential flow was observed. At higher flow rates the structure remained hidden by a spatially almost homogeneous behavior of the plumes. In this context, we mainly discuss the mechanism of re-distributing a finite mass of inert solutes over a large volume, due to macro- and micro-heterogeneities of the structure. (C) 2001 Elsevier Science Ltd. AU rights reserved.