Urban Solid Residues Research Articles

Urban Solid Residues Management: An Analysis from Sobral-CE/Brazil

Integrated Solid Residues Management can be understood as a way of designing, implementing and managing urban solid residues management systems, considering a broad participation of sectors of society and having sustainable development as a perspective. However, the excessive consumption of post-modern society has contributed to the increase in residues generation, especially in urban centers and, allied to this, the precarious Brazilian scenario regarding the management and logistics of disposal and treatment of residues, ending up trigger great harm in the environmental and socio-economic context. The main objective of this research was to analyze the current context regarding the management of urban solid residues in the city of Sobral-Ce, considering from the adequacy to PNRS, socio-environmental impacts associated with in appropriate residue disposal, as well as measures implemented by the city hall in mitigation of such impacts. The methodology used was descriptive and exploratory research. The results indicate that, despite the existence of public policies (in the initial phase) aimed at the correct disposal of solid residues in the city of Sobral, it was possible to verify during the field research that, in almost all neighborhoods of the city, there is inadequate accumulation of residues. Therefore, it is necessary, even if in the implementation phase, the elaboration of the integrated plans is really effective, as well as measures implemented by the city hall in the mitigation of such impacts.

Preliminary thermal evaluation of disposable babies diaper viewing energy recycling

Human population growth, high consumption and unsustainable management of products and services are exceeding the sustainable use of natural resources. The use of disposable diapers, not only baby but also geriatric ones, reaches a high value, increasing considerably the urban solid residue generation. Currently, all this urban solid residue goes to landfills, taking up to 400 years to decompose, as most of its components are derived from oil. Its use as energy source, as it is already done with the cane bagasse, would bring great benefits, such as power generation and waste reduction. The objectives of this work were to identify the composition of each layer of a disposable diaper for babies and estimate the potential energy through combustion, employing the thermal analytical techniques TG/DTG/DTA, aiming at the reduction in the waste disposed in landfills, contributing in this way to an effective solid waste residue management. The layer 1 presented an endothermic peak at 165 °C, suggesting the presence of polypropylene, and layer 2 presented an endothermic peak at 130 °C, possibly consistent presence of polyethylene according to the manufacturer’s information and infrared analyses. Through the DTA curves of layers 4, 5 and sodium polyacrylate (PSA), it is observed that the fusion temperatures of the polymer are around 425 °C indicating the presence of PSA in both layers. The disposable diaper combustion releases approximately 12 kJg−1, lower than the heat released from sugarcane that is around 17 kJg−1; if used to obtain energy would help the removal of the diaper from the environment by reducing space occupied by that residue in landfills, contributing to environmental sustainability.

Analysis of Practicality for the Place of an Incinerator of Urban Solid Residues in the State of Tlaxcala

Analysis of Practicality for the Place of an Incinerator of Urban Solid Residues in the State of Tlaxcala

Devulcanization of waste tire rubber by microwaves

The disposal of urban solid residues is an enormous problem, especially in the case of vulcanized rubbers like tires. The old practice of landfilling is out of use due to the rising land costs, environmental concerns, fire risks and the possibility of proliferation of mosquitoes and other disease-carrying vectors. Devulcanization is shown to be an effective technique for making rubbers to flow and to be remolded. However, this process not only breaks down sulphur links, but also creates new other bonds, modifying the structure of the material as a whole.In order to help understand structural modifications of ground tire rubbers (GTR) as a result of devulcanization by microwaves, this work proposes an in-depth study of the chemical modifications, flow and thermo-oxidative degradation behavior as a function of the exposure time of the GTR to microwaves. An important conclusion is that the final temperature reached by the sample is the primary factor responsible for the success of the process. Depending on the final temperature of the sample, different types of sulphur bonds can be broken. During the treatment, there is a balance between break down and formation of new bonds. Therefore, it is important to control the process carefully in order to avoid degradation of the main chains. Tires usually are composed of a mixture of synthetic and natural rubbers, wherein natural rubbers could be more degraded by microwaves because carbon black is mainly found on this phase.

Sorting-Composting of Biodegradable Waste in the Municipality of Chief (Algeria): The Key Steps

In developing countries, sorting-composting of the urban solid residues (USR) requires the use of tools adaptable to the local conditions. To determine these optimal conditions of the process of sorting-composting of the biodegradable materials, an experiment was thrown at the level of the municipality of Chlef in Algeria. The parameters of follow-ups of the process of the fermentation were studied. The produced compost contain of the rates in N, P, K, % in Carbon (%C), % in Organic matter (%OM) and reports in C/N acceptable by the standard NFU 44 051 (the french standard of the organic amendments). The contents in elements metallic tracks (Cd, Cu, Pb, Ni and Zn) are lower than the limit standards. Also, the results of the analyses of the tests of phytotoxicity confirm that composts produced exhibit characteristics of organic amendments. These results give birth to an important crossroads for the treatment of the part fermentable of the urban solid residues in Algeria and specifically to Chief.

Analysis of deterioration and calorific value of urban solid residues

This study aimed to evaluate degradation and calorific value of urban solid residues (USRs) produced in the city of Campina Grande (PB), based on residues deposited in a bioreactor that simulates landfill conditions. The USR samples presented low thermal stability, because occur five stages of loss, from room temperature to 1000 °C, associated with volatilization of solvents (water and alcohol), the combustion of cellulose, natural rubber, putrescible organic matter and plastic materials, as well as oxides formed during process. USR studied have an estimated average calorific value of 15,678.98 J kg−1 that could generate 1,518,551.40 kW h−1 day of thermal energy or 303,710.28 kW h−1 day of electricity, with conversion efficiency of 20 %.

Analysis of a CHP plant in a municipal solid waste landfill in the South of Spain

The most effective strategy to manage and treat solid urban residues, with the least environmental impact as well as lowest economic and energy costs, is a challenge for sustainability in current society, who actually pay for the final management of these residues. This manuscript analyzes the potential of biogas generation in an urban solid residue treatment plant, and the potential use for cogeneration in situ at the landfill. The objective is to identify the energy potential associated with the landfill and its potential use to accelerate the evaporation of leachate through the supply of heat, reducing the risks of exceeding the collection capacity of the leachate ponds. The change in legislation for generation within the special regime in Spain (2014) introduced a sudden change in the direction of energy policies, which affected significantly the profitability of these facilities. This manuscript analyzes the application of both legislations, previous (2007) and current (2014), for the case of a cogeneration system installed in this landfill. The results obtained indicate that even with a much more restrictive legislation in force, acceptable values are obtained for the evaluation of the investment – however, better results were obtained for the previous legislation that favored the special regime. The new regulation constrains the maximum and minimum annual operating hours for landfill cogeneration. It results in relevant periods with limited use of biogas for electricity generation. Biogas storage for delayed future consumption in the same installation and biogas selling for external use in boilers are proposed as options for this biogas in excess. They can reduce greenhouse gases emissions from the non-used biogas and can improve the economic results of the facility.

Assisted attenuation of a soil contaminated by diuron using hydroxypropyl-β-cyclodextrin and organic amendments

Diuron desorption and mineralisation were studied on an amended and artificially contaminated soil. The amendments used comprised two different composted organic residues i.e., sewage sludge (SS) mixed with pruning wastes, and urban solid residues (USR), and two different solutions (with inorganic salts as the micronutrients and hydroxypropyl-β-cyclodextrin (HPBCD)). After applying micronutrients to activate the soil flora, 15.5% mineralisation could be reached after 150days, indicating that the soil has a potential capacity to mineralise the herbicide through biostimulation-assisted attenuation. Diuron mineralisation was also improved when HPBCD solutions were applied. Indeed, the extent of herbicide mineralisation reached 29.7% with this application. Moreover, both the lag phase and the half-life time (DT50) were reduced to 33 and 1778days, respectively, relative to the application of just micronutrients (i.e., 39 and 6297days, respectively). Organic amendments were also applied (i.e., USR and SS) on the contaminated soil: it was found that the diuron mineralisation rate was improved as the amendment concentration increased. The joint application of all treatments investigated at the best conditions tested was conducted to obtain the best diuron mineralisation results. The micronutrient amendment plus 4% USR or SS amendment plus HPBCD solution (10-fold diuron initially spiked) caused an extent of diuron mineralisation 33.2 or 46.5%, respectively.

Production of heterologous cutinases by E. coli and improved enzyme formulation for application on plastic degradation

Background: The hydrolytic action of cutinases has been applied to the degradation of plastics. Polyethylene terephthalate (PET) have long half-life which constitutes a major problem for their treatment as urban solid residues. The aim of this work was to characterize and to improve stable the enzyme to optimize the process of degradation using enzymatic hydrolysis of PET by recombinant cutinases. Results: The wild type form of cutinase from Fusarium solani pisi and its C-terminal fusion to cellulose binding domain N1 from Cellulomonas fimi were produced by genetically modified Escherichia coli . The maximum activity of cutinases produced in Lactose Broth in the presence of ampicillin and isopropyl β-D-1-thiogalactopyranoside (IPTG) was 1.4 IU/mL. Both cutinases had an optimum pH around 7.0 and they were stable between 30 and 50ºC during 90 min. The addition of glycerol, PEG-200 and (NH 4 ) 2 SO 4 to the metabolic liquid, concentrated by ultra filtration, stabilized the activity during 60 days at 28ºC. The treatment of PET with cutinases during 48 hrs led to maxima weight loss of 0.90%. Conclusions: Recombinant microbial cutinases may present advantages in the treatment of poly(ethylene terephthalate) PET through enzymatic treatments.

Níveis de irrigação na formação de mudas de eucalipto com utilização de resíduo sólido orgânico urbano

SUMMARY: The increasing production of residues produced by the human population, especially the Urban Organic Solid Residue (U.O.S.R.), has been requiring scientific knowledge that enables the planet environmental maintenance. This research aimed to study the effect of the irrigation that is accomplished through the daily determination of the evapotranspiration by the method of the A rank tank, multiplied by the culture coefficient, associated with the use of U.O.S.R. for the formation of eucalyptus seedlings. The research was developed at the Sao Paulo State University (UNESP), Jaboticabal - SP, Brazil, adopting as statistic design the entirely casualized factorial scheme. Eleven substrates were used: two types of soils, an eutrophic red latosol and a dystrophic red latosol, with and without chemical fertilization, six mixtures of soil and U.O.S.R., and only one of U.O.S.R.. It was used specific containers for the direct eucalyptus sowing from the variety Citriodora Hooker. Four levels of irrigation were used and 50; 75; 100 and 130% of the daily determination. The data collected and analyzed statistically show that in some cases the irrigation when associated with the use of U.O.S.R., made it possible for a better formation of eucalyptus seedlings.

Relation between kinetic parameters for reactions of organic matter degradation in waste environmental matrix

The organic fraction of urban solid residues disposed of in sanitary landfills during the decomposition yields biogas and leachate, which are sources of pollution. Leachate is a resultant liquid from the decomposition of substances contained in solid residues and it contains in its composition organic and inorganic substances. Literature shows an increase in the use of thermoanalytical techniques to study the samples with environmental interest, this way thermogravimetry is used in this research. Thermogravimetric studies (TG curves) carried out on leachate and residues shows similarities in the thermal behavior, although presenting complex composition. Residue samples were collected from landfills, composting plants, sewage treatment stations, leachate, which after treatment, were submitted for thermal analysis. Kinetic parameters were determined using the Flynn–Wall–Ozawa method. In this case they show little divergence between the kinetic parameter that can be attributed to different decomposition reaction and presence of organic compounds in different phases of the decomposition with structures modified during degradation process and also due to experimental conditions of analysis.

Estrategia para la educación ambiental en comunidades cubanas

In the studied province polluting sources generated by the industrial activity exist and agricultural that is developed there and the problem was identified: Insufficiencies in the handling of agricultural the urban solid residues and. But an adapted handling of residues needs men trained with an environmentalist conviction, that it begins in the home and the schools. This justified the design of a communitarian strategy integrated of environmental education as guide to diagnose socio-educational needs and possible routes for a change in bring back to consciousness and the behavior of the community and a sustainable development. The environmental perception was diagnosed, physical state and of the environmental management of the handling of residues, using participating observations, surveys, interviews, etc. designed seven programs: Cultural, Communication, health, Qualification, scholastic education, handling of residues and embellishment of the community. The evaluation was conceived like an internal process of management.

Saúde coletiva, resíduos sólidos urbanos e os catadores de lixo

The article approaches the issues of environmental production and the generation of urban solid residues, in particular the environment and health concept while social representation. From a bibliographical revision it argues the incorporation of the themes of health and environment in the practical field of knowledge and of interconnection with the Public Health. In this context it associates the question of the social exclusion generated by the form of production and consumption of the after-modern society, introducing the garbage collectors as a vulnerable population group.

Energia de briquetes produzidos com rejeitos de resíduos sólidos urbanos e madeira de Eucalyptus grandis

O incentivo ao consumo e à produção em grande quantidade na sociedade atual gera, exageros de resíduos sólidos urbanos que, em alguns casos, podem ser utilizados para a geração de energia. Neste sentido e visando reduzir os resíduos dos aterros municipais e gerar energia, buscou-se produzir briquetes com mistura de rejeitos de resíduos sólidos urbanos (RRSU) e resíduos de madeira de Eucalyptus grandis. Os briquetes foram fabricados com 0, 5, 10, 15, 20 e 25% de RRSU na mistura com resíduos madeireiros contendo 12% de umidade. Os parâmetros analisados para a escolha da melhor mistura, foram: análise de combustibilidade x cinzas, resistência e energia utilizável. Os briquetes com até 10% de RRSU se mostraram com baixa resistência e os acima de 15% apresentaram grande aumento no teor de cinzas; portanto, os que melhor atenderam aos requisitos combustibilidade x cinzas e resistência mecânica, foram aqueles com 15% de RRSU, pois não se conhece a procedência das cinzas. Considerando-se a energia utilizável, o briquete com 25% de RRSU é o que apresenta maior poder calorífico útil na ordem de 17.175 kJ kg-1 motivo pelo qual se indica a produção de briquetes com adição RRSU; ressalta-se, porém, a necessidade de estudos sobre a emissão de gases.

Report: The current situation of sanitary landfills in Brazil and the importance of the application of economic models

We present the development stage of the sanitary landfills in Brazil in the context of urban solid residue management, demonstrating the necessity and importance of the employment of economic models. In the article, a cost estimate model is proposed as the basis for studies to be applied by sector management, including the city council, companies, consultants and engineers, contributing to the choice of new areas, public bids, municipal consortia and private public partnerships.

Kinetic studies of urban solid residues and leachate from sanitary landfill

Urban solid residues are constituted of food remaining, grass leaves, fruit peelings, paper, cardboard, rubber, plastic, etc. The organic fraction formed represents about 50% during the decomposition yields biogas and leachate, which are sources of pollution. Residue samples were collected from the landfill in different and cells from several ages and the corresponding leachate, both after treatments, were submitted to thermal analysis. Kinetic parameters were determined using Flynn–Wall–Ozawa method. The linear relation between the two kinetic parameters (ln A and E) was verified for organic residue urban’s samples, but not for leachate’s sample. The occurred difference can be attributed to the constituents present in leachate.

Application of ultra-high-pressure liquid chromatography–tandem mass spectrometry to the determination of multi-class pesticides in environmental and wastewater samples: Study of matrix effects

An ultra-high-pressure liquid chromatography–tandem mass spectrometry (UHPLC–MS/MS) method for the determination of 37 pesticides (herbicides, insecticides and fungicides) in environmental and wastewater has been developed. To efficiently combine UHPLC with MS/MS, a fast-acquisition triple quadrupole mass analyzer was used. This analyzer (minimum dwell time, 5ms) allows acquiring up to three simultaneous transitions in the selected reaction monitoring mode for each compound assuring a reliable identification without resolution or sensitivity losses. A pre-concentration step based on solid-phase extraction using Waters Oasis HLB cartridges (0.2g) was applied with a 100-fold pre-concentration factor along the whole analytical procedure. The method was validated based on European SANCO guidelines using surface, ground, drinking and treated water (from an urban solid residues treatment plant) spiked at two concentration levels (0.025 and 0.1μg/L), the lowest having been established as the limit of quantification objective. The method showed excellent sensitivity, with instrumental limits of detection ranging from 0.1 to 7pg. It was applied to environmental water samples (ground and surface water) as well as to samples of urban solid waste leachates (raw leachate and treated leachate after applying reversed osmosis) collected from a municipal treatment plant. Matrix effects have been studied in the different types of water samples analyzed, and several isotope-labelled internal standards have been evaluated as a way to compensate the signal suppression observed for most of the compounds studied, especially in wastewater samples. As a general remark, only those pesticides which response was corrected using their own isotope-labelled molecule, could be satisfactorily corrected in all type of samples, assuring in this way the accurate quantification in all matrix samples.

Microstructure and mechanical properties of gypsum composites reinforced with recycled cellulose pulp

The use of waste fibers for the reinforcement of brittle matrices is considered opportune for the sustainable management of urban solid residues. This paper examines the microstructure and mechanical properties of a composite material made of gypsum reinforced with cellulose fibers from discarded Kraft cement bag. Two different kinds of gypsum were used, natural gypsum (NG) and recycled gypsum (RG), both with an addition of 10% by mass of limestone. For the production of samples, slurry vacuum de-watering technique followed by pressing was evaluated revealing to be an efficient and innovative solution for the composites under evaluation. The composite was analyzed based on flexural strength tests, scanning electron microscopy (SEM) imaging, secondary electron (SE) detection, and pseudo-adiabatic calorimetry. The morphology of the fractured surfaces of flexural test samples revealed large gypsum crystals double the original size surrounding the fibers, but with the same overall aspect ratio. Natural fibers absorb large amounts of water, causing the water/gypsum ratio of the paste to increase. The predominance of fiber pullout, damaged or removed secondary layers and incrusted crystals are indicative of the good bonding of the fiber to the gypsum matrix and of the high mechanical resistance of composites. This material is a technically better substitute for the brittle gypsum board, and it stands out particularly for its characteristics of high impact strength and high modulus of rupture.

EFEITO DA IRRIGAÇÃO E UTILIZAÇÃO DE LIXO ORGÂNICO NA FORMAÇÃO DE MUDAS DE EUCALIPTO

Mesmo quando não se encontram em áreas agrícolas, o descarte de resíduos orgânicos, quase sempre não ocorre dentro de especificações adequadas. Dentro desta ótica fica clara a necessidade de se buscarem parâmetros mais seguros para o uso desses resíduos, permitindo a sustentabilidade dos ecossistemas, com mínimas alterações. O uso imediato à coleta, do Resíduo Sólido Orgânico Urbano (R.S.O.U.), sem a prática da compostagem, submetendo-o a dessecagem, trituração e aplicação no solo, pode ser a solução para a eliminação da contaminação do lençol freático proporcionada pelo acúmulo desse material de forma concentrada e localizada, quer seja a céu aberto, ou na prática da compostagem. No Brasil e no Mundo, ainda não se produziu informações consistentes que possibilitem conhecimentos suficientes, para tomadas de decisões que estão sendo exigidas, em razão do crescente volume de resíduos produzidos e os impactos ao meio ambiente. Este trabalho objetivou estudar o efeito da irrigação associada ao uso de R.S.O.U. para formação de mudas de eucalipto. A pesquisa foi desenvolvida na Faculdade de Ciências Agrárias e Veterinárias - UNESP, Campus de Jaboticabal, SP. O delineamento estatístico adotado foi o esquema fatorial inteiramente casualizado. Foram utilizados onze substratos: dois tipos de solos (Latossolo Roxo e Latossolo Vermelho Escuro), com e sem adubação mineral, seis misturas de solo e R.S.O.U., e um utilizado somente R.S.O.U. Sementes de eucalipto var. Citriodora Hooker, foram semeadas diretamente em tubetes e irrigadas com base em dois métodos de quantificação da água (tanque classe "A" e determinação da massa), em quatro níveis (50, 75, 100 e 130% da evapotranspiração). Os dados coletados e analisados estatisticamente demonstraram que diferentes doses de R.S.O.U., não compostado previamente, misturadas aos solos destinados à produção de mudas de eucalipto, causam efeitos negativos na sobrevivência das plantas, sendo mais evidentes para doses acima de 20% e a irrigação conduzida com base no método de pesagem foi mais eficiente na manutenção das plantas.

Formação de mudas de eucalipto com utilização de lixo orgânico e níveis de irrigação calculados por dois métodos

O estudo das características e das possibilidades de utilização de Resíduo Sólido Urbano (R.S.U.) e mais especificamente de Resíduo Sólido Orgânico Urbano (R.S.O.U.), no Brasil e no Mundo, ainda não produziu informações que possibilitem conhecimentos suficientes para tomadas de decisões que estão sendo exigidas, em razão do crescente volume de resíduos produzidos e os impactos ao meio ambiente. Este trabalho teve o objetivo de estudar o efeito da irrigação associada ao uso de R.S.O.U. para formação de mudas de eucalipto. A pesquisa foi desenvolvida na UNESP, Câmpus de Jaboticabal - SP, sendo adotado como delineamento estatístico o esquema fatorial inteiramente casualizado. Foram utilizados 11 substratos: dois tipos de solos (um Latossolo Vermelho eutrófico e um Latossolo Vermelho distrófico), com e sem adubação química, seis misturas de solo e R.S.O.U., e um utilizando somente R.S.O.U. Sementes de eucalipto var. Citriodora Hooker foram semeadas diretamente em topetes e irrigadas com base em dois métodos de quantificação da água evapotranspirada (tanque Classe A e determinação da massa), em quatro níveis (50; 70; 100 e 130% da evapotranspiração). Os dados coletados e analisados estatisticamente demonstraram que doses acima de 20% de R.S.O.U. na mistura, em solos destinados à produção de mudas de eucalipto, causam efeitos negativos na sobrevivência das plantas.