Life Cycle Assessment of prospective MSW management based on integrated management planning in Campo Grande, Brazil.

A crucial first step in transforming problematic waste management into sustainable integrated systems is comprehensive planning and analysis of environmental and socio-economic effects. The work presented here is a Life Cycle Assessment (LCA) that addressed the environmental performance of prospective development pathways for the municipal solid waste (MSW) management system in a large urban area, i.e. Campo Grande, Brazil. The research built on data and expanded the main development pathway proposed in the municipalities integrated waste management plan, which covers a period of 20 years (2017-2037). The system progression was assessed for milestone years (5-year intervals) considering projections of future population and waste generation growth, as well as addressing the development of surrounding systems, such as energy production. Results reveal that the rather conservative planned development pathway, which is largely based on gradual increase in selective collection, could successfully counter negative environmental externalities that would otherwise materialize due to increasing waste generation. A second, more ambitious, pathway with additionally scheduled actions to treat mixed MSW and upgrade certain treatment technologies (e.g. from composting to anaerobic digestion of collected organics), was used to illustrate a potential range for significantly higher impact reduction and even positive externalities, given a zero burden approach before waste generation.

Alternative construction and demolition (C&D) waste characterization method proposal / Proposta de método alternativo para identificação da composição de resíduos de construção civil (RCC)

ABSTRACT Construction and demolition waste generally represents the majority of solid waste generated in Brazilian cities, and characterization of this waste stream is still incipient. Therefore, to support managers in the process in the diagnostic phase, this study consisted in a proposal qualitative characterization method in field, that use of construction and demolition (C&D) waste generation indicators. For this, a survey which have been divided in two stages: quantitative characterization based on a three-indicator-analysis of C&D waste generation and qualitative characterization consists of an image analysis procedure on C&D waste samples. The qualitative characterization method has proved to be efficient for samples with high-volume parts. However, this method is limited to represent characterizations that contain residues which might cover the other C&D waste types, for example, plastic sheeting, cardboard and packaging. This method of image analysis is suitable for use in early diagnostics, which require fast results about C&D waste composition.

RESUMO Os resíduos da construção civil podem representar a maior parte dos resíduos sólidos gerados nos municípios, e o conhecimento de sua composição ainda é limitado. Para apoiar gestores na fase de diagnóstico desses resíduos, este estudo propõe um método de campo que forneça a sua caracterização qualitativa apoiado em indicadores de geração. Para tanto, a pesquisa foi dividida em duas etapas: caracterização quantitativa baseada na análise de três indicadores de geração de resíduos da construção civil; e caracterização qualitativa, que consistiu em um procedimento de análise de imagem de amostras de resíduos da construção civil. O método de caracterização qualitativa provou ser eficiente para amostras volumosas. No entanto, esse método foi considerado limitado para representar caracterizações que contêm resíduos que podem abranger outros tipos de resíduos de construção civil, a exemplo de plásticos, papelão e embalagens. O método de análise de imagem mostrou-se adequado para uso em diagnósticos preliminares, os quais exigem resultados rápidos sobre a composição dos resíduos da construção civil.

Biomass growth and its mobility in an AnSBBR treating landfill leachate.

This work used a pilot scale (with a total volume of 1300 L) Anaerobic Sequencing Batch Biofilm Reactor (AnSBBR) to treat landfill leachate from São Carlos-SP (Brazil) as well as to evaluate the biomass growth and its behavior. Biomass from the bottom of a landfill leachate stabilization pond was immobilized in polyurethane foam cubes as inoculum. The leachate characteristics varied during the experiment. Ethanol or volatile fatty acids were added as additional substrate when the leachate was temporarily recalcitrant. After acclimation, the AnSBBR presented efficiency over 70% (COD removal). A mass balance model, biomass sampling and temporal concentration profiles were performed to obtain a biomass yield coefficient of YX/S = 0.0251 ±â€¯0.0006 gTVS gCOD removed (r2 = 0.999). Additionally, it was observed that a variable fraction of the attached biomass may detach itself or present mobility during the batch time, however returning to fixed bed depending on the substrate type and concentration. This behavior has never been reported by the literature for attached biomass.

Assessment of the use of organic composts derived from municipal solid waste for the adsorption of Pb, Zn and Cd.

Waste management is a continuous global need. To minimize problems arising from municipal solid waste (MSW) disposal, composting has emerged as a simple alternative for the organic fraction of the waste. The composting process generates organic composts with a high metal retention capacity for potentially toxic elements (PTE). Thus, our objective was to examine how different composting methods (windrow composting, wire mesh composting bin, and passively aerated static pile composting) affect the final product, and how the characteristics of the generated composts influence their adsorption capacity for the lead (Pb), zinc (Zn) and cadmium (Cd) elements from mining waste. Therefore, the physical and chemical properties of Brazilian composts were investigated, as well as their adsorption capacities, through batch equilibrium tests with Pb, Zn and Cd in single-element solutions. All composts revealed promising adsorption characteristics, including a near-neutral pH (6.4-7.7); a negative ΔpH (-0.4 to -1.0); oxidizing conditions (Eh between +267.67 and + 347.00 mV); a considerable presence of organic matter (193.92-418.70 g kg-1); a substantial (albeit very varied) cation exchange capacity (29.00-75.00 cmolc kg-1); and significant porosity (pore volume between 0.01113 and 0.05400 cm3 g-1). These results showed that the composts share similar intrinsic characteristics, indicating that the different composting methods influenced subtly the physical and chemical properties of the final products. Overall, the removal selectivity follows the order Pb > Cd > Zn, with the removal percentage ranging from 94.0 to 99.6% for Pb, 55.4-89.8% for Cd and 22.1-64.0% for Zn. Thus, the joint assessment of the characterization and adsorption results shows evidence that composts, a low-cost organic material produced from waste, may be promising as alternative reactive materials for remediation of soils contaminated by Pb, Zn and Cd.

Environmental assessment of existing and alternative options for management of municipal solid waste in Brazil.

Life cycle assessment (LCA) was used to evaluate and compare three different categories of management systems for municipal solid waste (MSW) in Brazil: (1) mixed waste direct disposal systems, (2) separate collection systems, based on wet-dry streams, and (3) mixed waste mechanical-biological systems, including materials recovery. System scenarios were built around main treatment techniques available and applicable in developing countries, and considered barriers as well as potential synergies between waste management and other industrial production. In the first category systems, we measured the impact magnitude of improper disposal sites (semi-controlled and controlled dumps) still used for approximately 40% of collected MSW, and found that sanitary landfills could decrease it 3-5 fold (e.g. GWP, from 1100-1200 to 250-450 kg CO2 eq. t-1 waste). As an alternative, waste incineration did not show significant benefits over sanitary landfilling, due to limitations in energy utilization and the low-carbon background electricity system. Category two of systems, revealed recycling benefits and the necessity as well as potential risks of biological treatment for wet streams. Simple wet-dry collection could result in relatively high levels of contamination in compost outputs, which should be mitigated by intensive pre- and post-treatment. Potential impact of air emissions from biological degradation processes was important even after anaerobic digestion processes. Biogas upgrading and use as vehicle fuel resulted in bigger savings compared to direct electricity production. Lastly, category three, mechanical-biological systems, displayed savings in most environmental impact categories, associated with materials recovery for recycling and refuse-derived fuel (RDF) production and utilization in cement manufacturing.

First-order kinetics of landfill leachate treatment in a pilot-scale anaerobic sequence batch biofilm reactor.

This paper reports the kinetics evaluation of landfill leachate anaerobic treatment in a pilot-scale Anaerobic Sequence Batch Biofilm Reactor (AnSBBR). The experiment was carried out at room temperature (23.8 ± 2.1 °C) in the landfill area in São Carlos-SP, Brazil. Biomass from the bottom of a local landfill leachate stabilization pond was used as inoculum. After acclimated and utilizing leachate directly from the landfill, the AnSBBR presented efficiency over 70%, in terms of COD removal, with influent COD ranging from 4825 mg L(-1) to 12,330 mg L(-1). To evaluate the kinetics of landfill leachate treatment, temporal profiles of CODFilt. concentration were performed and a first-order kinetics model was adjusted for substrate consumption, obtaining an average k1 = 4.40 × 10(-5) L mgTVS(-1) d(-1), corrected to 25 °C. Considering the temperature variations, a temperature-activity coefficient θ = 1.07 was obtained. Statistical "Randomness" and "F" tests were used to successfully validate the model considered. Thus, the results demonstrate that the first-order kinetic model is adequate to model the anaerobic treatment of the landfill leachate in the AnSBBR.

Integração de critérios técnicos, ambientais e sociais em estudos de alternativas locacionais para implantação de aterro sanitário / Integrating technical, environmental and social criteria in landfill sitting studies

A Política Nacional do Meio Ambiente tem como objetivo a conciliação do desenvolvimento econômico e social com a qualidade ambiental, e dispõe de vários instrumentos que procuram contemplara capacidade de suporte do meio. Assim, a discussão sobre a localização das atividades é uma etapa importante para a avaliação da viabilidade ambiental de um determinado empreendimento, notadamente em processos de licenciamento ambiental. O trabalho apresenta uma abordagem metodológica para integração de critérios técnicos, ambientais e sociais em estudos de alternativas de localização de aterros sanitários, com especial atenção à interação entre os aspectos ambientais e os elementos fundamentais de um projeto (a saber, requisitos locacionais e concepção tecnológica), aplicado em um estudo de caso em São Carlos (SP). Como resultados principais, destacam-se o maior foco nos impactos significativos e a possibilidade de envolvimento de segmentos importantes da sociedade previamente à elaboração dos estudos ambientais.

The National Environment Policy aims to reconcile economic and social development with environmental quality and has several instruments to address environmental issues within the decision making processes. Thus, the discussion about the location of activities is an important step in the evaluation of the environmental acceptability of aparticular activity, even though the systematic procedures do not require neither to the entrepreneur or to the government studies of sitting alternatives. This paper presents the integration of technical, environmental and social criteria in a landfill sitting study, in order to present a systematic integration of environmental factors and applies in a case study in São Carlos, Brazil. The results allowed the development of an environmental impact statement more focused on significant impacts and the participation of segments of society at early stages of project's development.

Reciclagem de lodo de esgoto em plantação de eucalipto: carbono e nitrogênio / Sewage sludge recycling in eucalypt plantation: carbon and nitrogen

O objetivo geral do trabalho desenvolvido foi avaliar como o lodo de esgoto (biossólido) altera os estoques de C e N em plantação de eucalipto. O estudo foi conduzido com aplicação de doses até 40 t ha-1 de biossólido, em base seca, para cultivo de Eucalyptus grandis. Os eucaliptos que receberam 10 t ha-1 de biossólido apresentaram igual desenvolvimento aos que receberam adubação mineral completa, produzindo, em média, 107,5 t ha-1 de biomassa acima do solo, 63 por cento a mais do que a testemunha. Esses tratamentos apresentaram também maiores valores de conteúdo de C e N na biomassa. O biossólido tratado com cal, aplicado em superfície, apresentou baixas taxas de decomposição e não contribuiu para aumentar os estoques totais de C e N no solo. O efeito do resíduo sobre o desenvolvimento das árvores é mais importante para fornecer entradas de material orgânico no sistema do que sua própria aplicação.

The general aim of this research was to evaluate as the sewage sludge (biosolids) modify C and N stocks in eucalypt plantation. The study was installed with application rates up to 40 t h-1 of dry matter biosolids in Eucalyptus grandis plantation. The eucalypts that received 10 t h-1 of biosolids presented even development that it received full mineral fertilizer, producing, on average, 107,5 t ha-1 of aboveground biomass, 63 percent the more than control. Those treatments also presented larger values of C and N contents in the biomass. The biosolids treated with lime, applied in surface, showed low decomposition rates and it didn’t contribute to increase C and N soil total stocks. The effect of residue on the development of trees is more important to supply input of organic material in system than own application.

Usinas de reciclagem e compostagem no Brasil - Características gerais dos sistemas existentes

Las usinas de reciclaje de residuos sólidos domiciliarios están dentro del manejo de nuevas tecnologías como una forma positiva del tratamiento de la basura. Este trabajo recomienda la realización de actividades para el mejoramiento de las operaciones

Aterros sanitarios: análise da reprodutibilidade de parámetros que influenciam o processo da digestao anaeróbia

El presente trabajo se desenvolvió a partir de la construcción experimental de rellenos sanitarios de residuos sólidos domésticos, en escala real, que han permitido el análisis del comportamiento de parámetros que controlan la digestión anaerobia de los residuos. La preocupación del autor fué verificar, estadísticamente, cuales son los parámetros relevantes en la digestión de residuos que forman el relleno experimental, durante el período de análisis. El material utilizado en este estudio es la basura domiciliaria de la ciudad de Sao Carlos, Estado de Sao Paulo