Ana Augusta Passos Rezende

AVALIAÇÃO DO POTENCIAL DE APROVEITAMENTO ENERGÉTICO DOS RESÍDUOS DE MADEIRA E DERIVADOS GERADOS EM FÁBRICAS DO POLO MOVELEIRO DE UBÁ - MG

O presente estudo avaliou o potencial de reaproveitamento energetico dos residuos de madeira e seus derivados gerados no Polo Moveleiro de Uba, MG. Paineis reconstituidos de MDF (medium density fiberboard), aglomerado e compensado foram caracterizados e classificados, identificando assim as oportunidades e possiveis limitacoes quanto a sua utilizacao. Por meio de diagnostico realizado em 11 fabricas de moveis, verificou-se que os residuos de madeira compreendem mais de 90 % do total dos residuos solidos gerados. Alem da grande quantidade gerada, nao foi identificada nenhuma acao integrada entre as fabricas do Polo para o adequado gerenciamento dos residuos, negligenciando seus riscos ambientais e sanitarios, bem como seu potencial energetico. Contudo, os teores de umidade e poder calorifico dos residuos demonstraram potencial para o seu reaproveitamento energetico atraves da producao de briquetes. Os gases gerados em ensaios de combustao dos residuos nao apresentaram substâncias ou compostos toxicos acima dos limites preconizados pelas normas ambientais, verificando, neste aspecto, um bom desempenho ambiental para o aproveitamento destes residuos conforme proposto pelo presente estudo. Entretanto, as cinzas dos residuos de aglomerado BP (baixa pressao) e FF (finish foil) apresentaram elevadas concentracoes de cromo, enquadrando-se como Classe I (perigosos), segundo a ABNT/NBR 10004/2004.

Membrane treatment of the bleaching plant (EPO) filtrate of a kraft pulp mill.

The objective of this study was to evaluate the use of membrane technology to treat oxygen and peroxide-reinforced extraction stage (EPO) filtrate from a kraft pulp mill bleach plant. Three different types of tubular membranes were tested in a pilot plant: (i) tight ultrafiltration (UF); (ii) open UF followed by nanofiltration (UF+NF); and (iii) nanofiltration (NF). According to the separation performance, considering the chemical oxygen demand (COD) and colour removal, permeate flux, operational simplicity and cost, the results indicated that the best option for treatment of (EPO) filtrates was the tight UF membrane. This membrane obtained a COD removal of 79% with a colour reduction of 86%. The effect of (EPO) filtrate UF treatment on the mill effluent treatment plant was evaluated. Compared with the actual mill effluent, the results indicated that if the UF permeate was recycled in the bleaching area, the COD reduction efficiency increased by 7%, the final effluent colour decreased by 8%, the biological sludge production decreased by 18%, and the energy consumption decreased by 40%. In the tertiary treatment plant, the coagulant dosage decreased by 40%, and the tertiary sludge production decreased by 46%.

Avaliação da utilização de composto orgânico produzido a partir dos resíduos de fábrica de celulose quanto aos níveis de organoclorados e metais

Bleached kraft pulp mill sludge may present traces of heavy metals and organochorine compounds even when ECF (elemental chorine free) bleaching sequences are used due to the presence of chlorine dioxide. The objective of this work was to evaluate the absorption potential of heavy metals and organochlorine compounds (PCDD and PCDF) by Brassica juncea when bio-sludge of an activated sludge plant and organic compost prepared from bio-sludge mixed with Eucalyptus bark of a bleached kraft pulp mill. The plants were cultivated in 0.63 dm3 pots in greenhouses during 73 days. The following parameters were monitored in the substrate and in the plants: Fe, Mn, Pb, Ni, Cu, Zn, Cr, Cl-, total organic carbon and AOX (adsorbable organic halogen compounds). Content of heavy metals in the soil after compost application was within the Brazilian legal standards for compost application. Traces of PCDD e PCDF were found in the substrate at concentrations lower than 0.5 ng I-TEQ/kg (ppt). These values were lower than the highest quality criteria of 17 ng I-TEQ/kg from Canada and Germany.

Irrigation of eucalyptus plantation using treated bleached kraft pulp mill effluent

The use of treated pulp mill effluent on eucalyptus plantation appears to be an attractive option for plant nutrition and water supply. It also constitutes a supplementary treatment process and a final disposal option for the mill effluent. This study aimed at the investigation and evaluation of the effects of bleached kraft pulp mill treated effluent on three typical Brazilian soils used for eucalyptus plantation. The effluent was characterized and five different application rates, defined according to the load of sodium, were tested in controlled environment experiments (greenhouse). After effluent application over a six month period an increase in the salinity of the studied soils was observed, although no soil dispersion was detected. The low content of some nutrients in the treated effluent indicated the need for fertilizer complementation. In general, the best biomass productivity and plant growth results were obtained in fine textured soil at a loading rate of 6.49 t Na ha(-1). The good response of the soil-plant system under different effluent application rates showed the feasibility for the eucalyptus irrigation if adequate management practices and monitoring are carried out.

Thermal drying of industrial sludge using forced aeration

ABSTRACT This study investigated an industrial biosludge drying system using hot gases from a coal furnace, seeking to increase the solids content of the biosludge above 50% (w.b.), considered suitable for combustion in biomass boilers. Biosludge was collected from a paper mill activated sludge plant. Biosludge mixtures with eucalyptus chips and eucalyptus bark in two different proportions (15% and 25%) were placed into a drying chamber. Hot gases generated by the furnace, with a flowrate of 0.64 ± 0.02 m3 s−1 at 100 ± 20°C, were applied to the piles through a blowing system. The results demonstrated that the 75% biosludge/25% eucalyptus bark mixture achieved the best drying ratio, increasing the total solids content from 31% to 72%, over a 5-h drying period. Nevertheless, all other treatments involving the addition of a bulking agent achieved solids content above 50%, confirming the positive effect of adding dried material to the sludge. These results indicate a potential use of hot gases that are currently available and released into the atmosphere by paper mills. GRAPHICAL ABSTRACT

The Use of Network Simplex Method for Planning the Incorporation of Recycled Paper Mill Sludge in Manufacturing of Ceramic Bodies

The final disposal of sludge from recycled paper mill effluent treatment plants is costly and demands large areas for landfilling. Environmentally sound alternative uses of the sludge, enabling economic valoration of this material appear to be advantageous to industry and to the environment. This paper evaluates the feasibility of the incorporation of paper mill sludge in manufacturing of ceramic bodies. The combination of different proportions of weak clay, strong clay and sludge from recycled paper effluent treatment plant for the production of ceramic bodies was determined by using the Network Simplex method planning of mixtures. Samples were prepared and burnt in oven at temperatures of 750, 850 and 950 °C. Physical, mechanical and environmental tests were carried out, in addition to chemical, microscopic and thermic analysis. The results demonstrated that the flexion resistance increased with the increase in temperature, while the absorption decreased at higher temperatures. The mixture design is efficient combining sludge addition at small fractions with large amount of clay, which demonstrate the viability of sludge incorporation for ceramic bodies manufacture, since the desired characteristics are observed.

Incorporation of Paint Waste from Furniture Painting Booth into Covering Mortar

Aligned with the world’s tendency of searching for sustainable technologies, the waste addition into materials of the civil construction is an interesting option for wastes that do not have proper destination. This work has the objective of studying the feasibility of incorporating paint waste from furniture painting booth, which currently does not have any correct ecological destination, into covering mortars and investigate if this addition brings any improvement in performance. For this purpose, it was prepared six compositions of covering mortars, with a cement-sand volume proportion of 1:6 and a Flow-table consistency of 260 mm +- 10mm, varying the waste percentage added among the proportions of 0%, 2%, 4%, 6%, 8% and 10% on the cement weight. It was determined, for each composition, the specific gravity and the air-entrained content in the fresh stage. For physical tests, it was moulded nine prismatic samples and one mortar substrate for the bond tensile strength test per mortar composition. It was determined the flexural and compressive strength in the hardened stage, the specific gravity, the water absorption coefficient due to capillary action and the bond tensile strength. Leaching tests were performed for environmental analysis of the mortars produced with waste addition. It was observed that all the mortars with waste received a similar classification to the mortar without waste, according to NBR 13281 [], and the leaching tests showed that mortars with waste were not ecologically dangerous, demonstrating the feasibility of the incorporation. In addition, mortars produced with waste presented an increase in the entrained air percentage, which might be a beneficial action of the paint waste.

Use of Leather Residue in the Manufacturing of Soil-Cement Bricks

This work is an analysis of incorporation of leather powder residue to soil in order to apply it in soil-cement bricks. The leather powder is a byproduct of the finishing step of leather manufacturing that contains chromium in its composition. This element, when in its hexavalent form, is carcinogenic. Experiments were performed regarding brick pressing, water absorption, simple pressing, leaching and solubilization so that the mixtures have the minimum requisites for using the brick. The doses were 0%, 10%, 15%, 20%, and 30% in volume of leather powder in soil. Only the 10% dose met the requisites of ABNT: NBR 8491:1984 that prescribes a minimum resistance of 2 MPa and absorption content lower than 20%. For this dosage, according to the limits stated in ABNT regulation NBR 10004:2004 , the leaching extract was classified as a Class II non-inert, which makes it possible to use it for civil construction purposes.

Evaluation of Incorporation of a Leather Waste Powder in Mortars for Construction Industry

This paper has the objective to evaluate the technical feasibility of incorporation of leather powder in mortars. First a physical characterization of aggregate was carried and then preceded to the dissolution of the leather powder in alkaline solution, in the proportion of 1:1:1 of waste, alkaline solution and water respectively, obtaining the processed waste. In the next step, it has been molded specimen using two reference recipes in terms of mass, 1:3 of cement and sand, and 1:1:6 of cement, hydrated lime and sand respectively, keeping constant the flow table consistency of 130 ±10 mm and 220±10 mm, for each respectively recipe. Two groups of mortars were produced: one without processed waste, one with 5% and one with 10% in ratio to the cement mass. Tests had been carried such as compressive strength to axial compression, tensile strength to diametrical compression, and adherence strength on surfaces. The resistance tests performed; also the analyses of the leachate and solubilized extracts confirmed the feasibility of incorporation of leather powder in mortars.

Evaluation of the Potential of Waste from Pulp Production (Grits) in its Use in Mortar: Physical and Chemical Characterization

The grits is an inorganic solid residue generated during the Kraft process by the pulp and paper industry, which presents in its composition the main ingredients of Portland cement. According to some authors, the grits can be classified as a non inert, non hazardous, granular solid industrial waste. With this in mind, a study was proposed with the objective of evaluating, initially, the applicability of grits in mortar, by means of physical and chemical testing. The physical evaluations were realized through the following tests: determination of bulk gravity saturated - surface - dry (SSD) and water absorption; determination of the pulverulent material content; and the determination of particle size distribution. To chemically test the grits, a reading of the metal concentrations present in the grits was realized as well as an analysis of the leaching and solubilization extracts. It was concluded that the addition of grits to mortar is a potential alternative.