Claudio Fernando Mahler

Reverse logistics in the Brazilian construction industry

In Brazil most Construction and Demolition Waste (C&D waste) is not recycled. This situation is expected to change significantly, since new federal regulations oblige municipalities to create and implement sustainable C&D waste management plans which assign an important role to recycling activities. The recycling organizational network and its flows and components are fundamental to C&D waste recycling feasibility. Organizational networks, flows and components involve reverse logistics. The aim of this work is to introduce the concepts of reverse logistics and reverse distribution channel networks and to study the Brazilian C&D waste case.

A comparative analysis of CMMI software project management by Brazilian, Indian and Chinese companies

This article presents and discusses the perception of skilled professionals working in the Brazilian, Chinese and Indian software industries about their use of Capability Maturity Model Integration. About 429 employees from 19 software production companies that use the model took part in the study. Multivariate analysis methods, such as factorial analysis, were used to identify the interdependence between multiple variables. This led us to six factors: software project development, quality and productivity, professional career, team/working environment, problem identification and analysis and modeling. Three different analysis dimensions (country, company’s maturity level and company size) were investigated to assess the impact of the CMMI model on the six factors, which were defined for each of these dimensions.

Erosão superficial em argissolo amarelo sob cultivo perene e com pousio florestal em área de relevo montanhoso

The mountainside region of Rio de Janeiro (Regiao Serrana Fluminense) has many freshwater springs and the State´s largest remaining area of Atlantic Rainforest. It is important to know and control the harmful effects of soil erosion in order to harmonize environmental preservation with the intensive vegetable production in this mountain region. The purpose of this paper was to study soil loss by erosion and the hydrological components in an area with a slope gradient of 65 cm m-1. The study area consisted of plots with vegetable production in a rotation system, with banana and of a five-year-old forest fallow in a small watershed of the municipality of Bom Jardim. Three experimental plots of 88.0 m2 each (4 x 22 m) were installed to monitor soil loss, runoff and soil water dynamics. Soil characterization was performed by physic, chemical and mineralogy analysis. The highest soil erosion loss was recorded in the critical period between September and March, with approximately 30t ha-1 yr-1 from the annual crops and 10 t ha-1 yr-1 from forest fallow in the first year of development. The soil properties that correlated best with erosion were texture and the soil aggregate stability index. It was concluded that the time of soil use for vegetable cultivation and forest fallow can affect the maintenance of natural resources in this area, reducing slope stability and accelerating the erosive processes.

Diffusion and sorption experiments using a DKS permeameter

Abstract The analysis of contaminant transport through clay liner is a relevant aspect in the design of industrial, urban and mining waste disposal systems, since these areas must be designed and operated to prevent contaminating substances from reaching underground water systems in unacceptable concentrations. The design requires an estimate of the potential contaminant transport rate. However, before any attempt at quantification can be made, values for transport mechanism control parameters must be established. Clayey materials are frequently used as contaminant barriers. In these materials, which have low hydraulic conductivity, the main contaminant transport mechanism is molecular diffusion. Parameters controlling transport for these conditions are the diffusion coefficient and sorption parameters. These parameters depend on soil constituents and characteristics as well as on the chemical constitution of the contaminant. The great complexity of the factors involved makes it necessary to determine the parameters of each type of soil. This paper discusses an equipment called DKS permeameter (diffusion, convection, sorption), for the study of soil-contaminant transport mechanisms, designed at the Institute for Soil Mechanics of the Ruhr-University Bochum, and some results obtained from its use at COPPE/Federal University of Rio de Janeiro (UFRJ), Brazil. This equipment determines the effective diffusion coefficient and sorption parameter with a better reflection of field conditions. The soil under study is a mix of sodium–bentonite that has low hydraulic conductivity (k=10 −9 cm / s ) with adequate liner characteristics. The result indicated the relevance of determining sorption parameters for structured soils, since the sorption perceived from batch test results using pulverised soil represents maximum soil capacity. Designs based on this parameter would overestimate the attenuation capacity of the liner.

Phytoremediation of metals: a numerical analysis.

A finite element code was used for investigating the effect of some relevant characteristics of a phytoremediation project (crop type and density, presence of an irrigation system, soil capping and root depth). The evolution of the plume of contamination of Cd2+, Pb2+, and Zn2+ was simulated taking into account reactive transport and root processes. The plant contaminant uptake model was previously calibrated using data from greenhouse experiments. The simulations adopted pedological and climatological data representative of a sub-tropical environment. Although the results obtained were specific for the proposed scenario, it was observed that, for more mobile contaminants, poor water conditions favor stabilization but inhibit plant extraction. Otherwise an irrigation system that decreases crop water stress had an opposite effect. For less mobile contaminants, the remediation process did not have appreciable advantages. Despite its simplifying assumptions, particularly about contaminant sorption in the soil and plant system, the numerical analysis provided useful insight for the phytoextraction process important in view of field experiments.

Recycling of Waste Electrical and Electronic Equipment, a Case Study: Brazil

Electrical and electronic equipment is one of the most dynamic sectors of the economy, comprising 4.5% of the Brazilian gross domestic product (GDP) [1]. This market is growing faster than the country’s GDP. Although business volumes are high, there is no formal specific structure for treatment of waste electrical and electronic equipment (WEEE) in Brazil. A general law on solid waste was approved by the Congress and signed by the president in August 2010, but further enabling regulations still need to be issued.

Tensiometer Development for High Suction Analysis in Laboratory Lysimeters

This paper presents results when using a tensiometer designed in the Soil Mechanics Laboratory at COPPE/UFRJ, and several other instruments. This new instrument measures suction values up to 1500 kPa. In more typical tensiometers, the cavitation of the system hinders the measurement of suction with values over 100 kPa. Ridley and Burland (1993) designed a new model of tensiometer to measure suction of more than 100 kPa. Mahler et al. (2002) presented a new tensiometer with which suction values up to 350 kPa were measured. This paper introduces an updated model of a tensiometer, using a variation of the equipment proposed by Mahler et al. (2002). The updated model worked extremely well and cost little to build. The equipment used allows suction to be measured relatively quickly and, as previously stated, is economical to produce (about US

State of the Art of Phytoremediation in Brazil—Review and Perspectives

300). To date, the range of suction levels that can be measured reaches 1500 kPa with no difficulty. The tests were carried out in two boxes of 160× 50× 60 cm under laboratory conditions. The equipment used included a 15 m.c.a. ceramic block pressure sensor, de-aerated water and a special acrylic tube specifically designed for this instrument. The results were compared to two simple automated tensiometers and equivalent tensiometers. In general very good results were obtained. The main final remarks so far are as follows:

Analytical study of the performance of a geomembrane leak detection system.

The pollution of terrestrial and aquatic environments with heavy metals is a serious concern on a worldwide scale. Trace elements can be highly toxic and carcinogenic for human health while also detrimental to animal and plant life of ecosystems surrounding contamination hotspots. Phytoremediation is a low-cost and environment-friendly plant-based technique to alleviate polluted areas, which constitutes a viable alternative to other complex, costly, and often harmful traditional methods. Phytoremediation is particularly interesting for Brazil, given the country’s rich biodiversity and climate. This mini-review covers some of the most important results in phytoremediation studies carried out in Brazil to date, with a particular focus on the potential of the Brazilian flora for phytostabilization and phytoextraction, the two main subcategories of phytoremediation. Moreover, it includes data from two previously unpublished trials about phytoremediation of metal-polluted soil and water with vetiver grass and four wetland macrophytes (water hyacinth, creeping river grass, alligator weed, and water lettuce).

Waste to Energy in Brazil

The electrical detection of leaks in geomembranes is a method that allows identifying leakage of contaminants in lined facilities (e.g. sanitary landfills, pollutant ponds, etc.). The procedure in the field involves placing electrodes above and below the geomembrane, to generate an electrical current, which in turn engenders an electric potential distribution in the protective layer (generally a clayey soil). The electric potential will be greater in areas with higher current density, i.e. near leaks. In this study, we combined models from the literature to carry out a parametric analysis to identify the variables that most influence the amplitude of the electrical signals produced by leaks. The basic hypothesis is that the electrical conduction phenomena in a liner system could be depicted by a direct current circuit. After determining the value of the current at the leak, we calculated the electric potential distribution according to the model of Darilek and Laine. This enabled analysing the sensitivity of the parameters, which can be useful in the design of landfills and facilitate the location of leaks. This study showed that geomembranes with low electrical resistance (owing to low thickness, low resistivity, or extensive area) can hinder the leak detection process. In contrast, low thickness and high resistivity of the protection layer magnify the leak signal.