José Fernando Thomé Jucá

Evaluation of landfill gas production and emissions in a MSW large-scale Experimental Cell in Brazil

Landfill gas (LFG) emissions from municipal solid waste (MSW) landfills are an important environmental concern in Brazil due to the existence of several uncontrolled disposal sites. A program of laboratory and field tests was conducted to investigate gas generation in and emission from an Experimental Cell with a 36,659-ton capacity in Recife/PE - Brazil. This investigation involved waste characterisation, gas production and emission monitoring, and geotechnical and biological evaluations and was performed using three types of final cover layers. The results obtained in this study showed that waste decomposes 4-5 times faster in a tropical wet climate than predicted by traditional first-order models using default parameters. This fact must be included when considering the techniques and economics of projects developed in tropical climate countries. The design of the final cover layer and its geotechnical and biological behaviour proved to have an important role in minimising gas emissions to the atmosphere. Capillary and methanotrophic final cover layers presented lower CH(4) flux rates than the conventional layer.

Potential Uses of Sewage Sludge in Highway Construction

AbstractThe sewage treatment plants generate, as by-products, large amounts of sludge containing harmful elements to the environment. This paper investigates the possibility of using 10% of sewage sludge by weight in pavement base layers. The soil stabilization technique was used to improve the residue properties to satisfy the minimum requirements for road bases. The intent of this stabilization technique was to use conventional additives as cement, lime, and emulsion. The main objective was to evaluate the strength behavior of the modified soil. Sludge-soil mixtures with different additive contents (2, 4, 6, and 8%) were prepared for testing. The modified soil samples were subjected to compaction, and then tested for the following parameters: California bearing ratio, unconfined compressive strength, indirect-tensile strength, resilient modulusa, and deterioration tests. Mechanical tests were used to estimate the optimum mix design. Test results indicated that the stabilization of mixtures of soil with ...

Acúmulo de metais pesados e capacidade de impermeabilização do solo imediatamente abaixo de uma célula de um aterro de resíduos sólidos

Studies concerning soil contamination and their mechanisms have been explored more and more due to the long term security requirements demanded for residue containment systems. In this sense, the accumulation of some heavy metals, the impermeabilization capacity of the soil directly below a cell of the solid waste landfill of the Muribeca county, and the physicochemical characteristics of the leachate were investigated. Concentration profiles of heavy metals and volatile solids in the soil indicated the existence of a contamination plume towards the bottom, also showing occurrence of a wide range of concentrations of the analyzed metals, related to the concentration of each species in the leachate. Preferentially, Lead, Copper and Manganese were the absorbed metals and they presented a mean saturation velocity of the plume of 2.3 x 10-2 m/year, indicating an advective-dispersive transport, in disagreement with the soil texture.

Ensaios de campo para determinação de emissões de biogás em camadas de cobertura de aterros de resíduos sólidos

This paper presents a field methodology used to determine emissions of biogas through the cover layers of municipal solid waste landfills, by means of simple, straightforward and inexpensive tests. The results from these studies indicated that the flow of methane (CH4) can reach values up to 150 kg/m2. year, representing 630,000 tons of CO2eq per year in a mere 20 hectares of landfill. The thickness of the cover layer, which ranged between 0.2 and 0.7 m, was not a relevant factor in the measured emissions, while the pressure of biogas in the contact layer-waste, with values above 500 Pa, favors the formation of microcracks on the soil of the cover layer, which increases the emissions of gases in these points.

Removal of ammonia nitrogen from leachate of Muribeca municipal solid waste landfill, Pernambuco, Brazil, using natural zeolite as part of a biochemical system.

The inadequate disposal of leachate is one of the key factors in the environmental impact of urban solid waste landfills in Brazil. Among the compounds present in the leachates from Brazilian landfills, ammonia nitrogen is notable for its high concentrations. The purpose of this study was to assess the efficiency of a permeable reactive barrier filled with a natural zeolite, which is part of a biochemical system for the tertiary treatment of the leachate from Muribeca Municipal Solid Waste Landfill in Pernambuco, Brazil, to reduce its ammonia nitrogen concentration. This investigation initially consisted of kinetic studies and batch equilibrium tests on the natural zeolite to construct the sorption isotherms, which showed a high sorption capacity, with an average of 12.4 mg NH4+.L−1, a value close to the sorption rates found for the aqueous ammonium chloride solution. A permeable reactive barrier consisting of natural zeolite, as simulated by the column test, was efficient in removing the ammonia nitrogen present in the leachate pretreated with calcium hydroxide. Nevertheless, the regenerated zeolite did not satisfactorily maintain the sorption properties of the natural zeolite, and an analysis of their cation-exchange properties showed a reduced capacity of 54 meq per 100 g for the regenerated zeolite compared to 150 meq per 100 g for the natural zeolite.

Uso de modelos de apoio à decisão para análise de alternativas tecnológicas de tratamento de resíduos sólidos urbanos na Região Sul do Brasil

The decision support models are important tools that can be used to analyze technological alternatives in the management and treatment of municipal solid waste (MSW) against several situations involving political, economic, environmental and social aspects. This study aimed to propose alternatives for appropriate treatment of MSW in the South Region of Brazil by surveying information and using two decision support models: AHP (Analytic Hierarchy Process) and Promethee II (Preference Ranking Organization Method for Enrichment Evaluations). The studied technologies were: recycling, composting, mechanical-biological treatment, anaerobic digestion, incineration with electricity generation and combined cycle (electricity and heat) and landfill with and without power generation. These technologies were hierarchically ranked in the models based on four criteria: environmental, social, economic and political. As a result, we proposed four possible technological arrangements for the South Region and these can be used as reference for studies in other geographic regions of Brazil.

Estudo e caracterização de propriedades da argila esmectita na remoção de corantes têxteis

The textile industry process, especially in dyeing and finishing steps, requires a large volume of water. The elimination of these toxic products is currently one of the most important subjects in pollution control, which has led researchers to seek new techniques and more powerful tools to reduce or eliminate the toxicity of wastewater formed in its different processes, always taking into account efficiency, low costs and the laws and regulations aimed at environmental protection. In this study we evaluated the application of a clay waste in processes of wastewater treatment for removal of textile dyes. A study was conducted to characterize the adsorbent through the analysis of surface area and pore volume (BET), as well as the analysis of the presence of smectite group minerals (X-ray diffraction). The optimization of the adsorptive process through the technique of factorial design was used. The BET analysis showed that the heat treatment caused a reduction in the surface area of 13.3%. However caused an increase of 21.16% in the pore size. The analysis of X-ray diffractograms of the samples indicated in nature, therefore, the presence of mineral groups smectite, kaolinite and mica (illite). The mineral quartz participation (d001 = 3.35 A) was also observed in all the minerals found in clay. With the help of factorial design for the two dyes, there was a significant influence in the process of variable mass, agitation speed and temperature. We obtained satisfactory results in the

Biogas recovery in an experimental MSW cell in Brazil: lessons learned and recommendations for CDM projects

Biogas emissions in municipal solid waste (MSW) landfills are a serious air-pollution problem both at the local and global level. Methane, the main gas produced from the decomposition of waste, is the second largest contributor of anthropogenic emissions of greenhouse gases. This situation demands attention in Brazil, where there are still approximately 4,000 open dumps in operation that contribute to environmental contamination. The pilot project developed at the Muribeca/PE Landfill aimed to evaluate the potential for biogas generation and analyse energy production from the deployment of an experimental cell with 36,659 tonnes of MSW and a pilot plant capable of generating 20 kW. The results showed that MSW decomposition was more intense and rapid than predicted in the international literature. The feasibility analysis showed that it is viable to include the sale of electrical energy in the project with pricing restrictions and that the viability is greatly increased when Certified Emission Reductions are included. The main lessons learned from the different phases of the study (design, implementation, pre-operation, monitoring, and operation) will be of great use as recommendations for future emission-reduction projects.

Análise da influência do plástico mole na resistência ao cisalhamento de resíduos sólidos urbanos

This thesis presents an analysis of the shear strength of municipal solid waste with reduced thermoplastic in landfills. Through laboratory testing was performed a comparative analysis between the two main thermoplastics (high and low density polyethylene) present in Brazilians landfills. It investigates the variation of the strength parameters of MSW if plastic bags are removed from supermarkets from tensile tests of plastics and direct shear tests of samples prepared with different percentages of mixed plastics to a granular material simulating solid waste stabilized,. The results confirm the importance of plastics, because they are responsible for the high values of strength parameters due to tensile forces caused by these fibers.

Preliminary assessment of the metal contaminant potential of the leachate produced in a controlled sanitary landfill, Muribeca, Pernambuco, Brazil. *

The Muribeca Sanitary Landfill is the biggest landfill in the Recife Metropolitan area. It occupies an area of 0.6km2 in the Jaboati%odos Guararapes County and receives a daily load of 2800tons of domestic, industrial and hospital solid wastes. The purpose of this work is a preliminary assessment of the contaminant potential load of the leachate produced in two of the cells of the landfill in relation to the soil, sediments and surface waters. In order to achieve this a systematic sampling was carried out during October of 2000. The leachate was sampled along the leachate drainage until its discharged into the Muribequinha stream and Jaboat50 river. The samples were submitted to chemical analyses by ICP/AES in order to determine Ag, Al, As, Ba, Cd, Cu, Fe, Mn, Ni, Pb and Zn. The results showed that, in the leachate, only Al, Fe and Mn were above the method detection limit (0,05mg din-3) in all analyzed samples. It was observed that the metal concentration decreased away fl-om the source, both in distance and in depth. The metal concentration in the leachate shows a 10-fold decrease for Al and Fe and a 20-fold decrease in Mn when it reaches Jaboatao River. Considering that the leachate flow during the year 2000 varied from 1.1 drn3 S-l (January-dry season) to 31.76 dm3 S-l (June-rainy season) the contaminant load that eventually reached the Jaboatao river varied from 0,05-1.58 dm3 S-l (Mn), 3.3-95.28 dm3S-l(Al) and 5,5-158.8 dm3S-l(Fe).