Este trabalho avaliou aspectos ambientais, culturais, econômicos, de segurança, sociais e tecnológicos da reciclagem de plástico pós-consumo na região metropolitana de Porto Alegre (RMPA). Os objetivos específicos são: (i) obter um panorama da reciclagem do plástico pós-consumo na RMPA; (ii) identificar benefícios e custos da cadeia de reciclagem do plástico pós-consumo; (iii) identificar problemas, causas e oportunidades relacionadas à triagem dos materiais recicláveis, à reciclagem e transformação de plástico pós-consumo na RMPA. Devido à falta de dados completos mais recentes, o panorama foi construído utilizando dados de 2010 (base de dados governamental e planos municipais de gestão integrada de resíduos sólidos). Entrevistas com atores da triagem de materiais recicláveis, comercialização de sucata plástica, reciclagem e transformação do plástico pós-consumo constituíram o segundo procedimento metodológico na coleta de dados. Foi apresentado um panorama considerando a coleta de resíduos recicláveis e sua triagem, a comercialização, reciclagem e processamento do plástico pós-consumo na RMPA. Não foram encontrados dados de RSU para seis cidades que compunham a RMPA, correspondentes a 9% de sua população. Desta forma estima-se que 91% da população geraram 255.712 toneladas de materiais recicláveis (41% de plásticos), que 22% dos plásticos foram reciclados e que 202.864 toneladas de materiais recicláveis foram enviadas para aterros. Além disto, foi verificado que existiam significativas diferenças de políticas ambientas e de eficiência na reciclagem entre as cidades avaliadas. Para o ano de 2010, cálculos econômicos demonstraram benefícios de R$ 32 milhões na reciclagem do plástico, descontados o custo da coleta seletiva e a manutenção dos centros de triagem. Adicionalmente, foi verificado existir capacidade ociosa nas recicladoras de plástico no Rio Grande do Sul. Considerando que dezoito cidades (81% da população) recuperaram somente 19% dos materiais recicláveis gerados na região através da triagem da coleta seletiva ou bruta, as prováveis causas do envio de grande quantidade de materiais recicláveis para o aterro são a baixa eficiência da população ao separar em casa os resíduos recicláveis dos demais resíduos e a baixa taxa de participação da população na coleta seletiva. Ainda faltava implantar coleta seletiva em dezesseis cidades da RMPA. Entretanto, o aumento na frequência da coleta seletiva poderia aumentar o índice de participação na maioria das cidades e o aumento do pessoal na triagem de coleta bruta poderia aumentar a recuperação de recicláveis. Além disto, R$ 150 milhões seria o benefício por reciclar 89.837 toneladas de materiais recicláveis enviados para o aterro em 2010. / This work aims to address environmental, cultural, economic, safe, social and technological aspects involved in the recycling scene of post-consumer plastics in the Porto Alegre Metropolitan Area (RMPA). The specific goals are to identify: (i) benefits and costs of sorting recyclable materials and recycling plastics; (ii) problems, causes and opportunities related to sorting of recyclable materials and post-consumer plastic recycling and processing in the RMPA. Owing to the lack of a more recent complete data base for the RMPA, the recycling scene was built from 2010 data (from integrated waste management plans and Brazilian government database). Interviews with actors involved in the post-consumer plastic recycling of the region were the second collection method used. The recycling scene in the region has been presented, considering collection, sorting, trading, transportation, mechanical recycling and re-processing. Municipal solid waste (MSW) data was not found for six cities, corresponding to 9% of the RMPA population. According to this study estimations, 91% of the RMPA population generated 255,712 tonnes of recyclable materials (41% of plastics), 22% of plastics were mechanically recycled and 202,864 tonnes of recyclable materials (44% of plastics) were sent to landfill sites. Furthermore, it was verified that there are significant differences of policies and recycling efficiency among the cities of the RMPA. For the year of 2010, economic calculations demonstrated benefits of R$32 million in plastic recycling, discounted the cost of the selective collection and sorting facilities maintenance. Additionally, it was verified that there is a surplus capacity in recycling companies of the region. Considering that 81% of the RMPA population (18 cities) recovered through selective collection only 19% of existing recyclable material in municipal solid waste, low efficiency in sorting recyclable waste at home and low participation rate of population in selective collection may be considered the primary causes of the problem related to the large amount of plastics arriving at the landfill in the RMPA. However, the increase in the selective collection frequency could also contribute to improve the participation rate in most cities of the region. Besides, R$150 million would be the benefit for recycling 89,837 tonnes of plastics, which were sent to landfill.

This study utilizes a cross-sectional quantitative study design that explores the perceptions of preparedness of advanced year Master of Social Work (MSW) students, regarding intimate partner violence (IPV) clients. Currently, there may be gaps in regards to adequately preparing students for serving intimate partner violence clients. This is an exploratory study and data is collected using self-report surveys, which include questions on: demographics, perceptions of preparedness, and education/training received on IPV. This study seeks to identify a correlation between the education/training that MSW students receive on IPV, and their levels of preparedness for serving IPV clients. This study hopes to gain a better understanding on which factors affect MSW students’ feelings of preparedness for serving IPV clients. The results indicated that perceptions of preparedness are associated with field training, field placement, age and gender. There was a positive relationship between field training and feelings that field placement prepared students for serving IPV clients, and a positive relationship between field training and feelings of having sufficient knowledge in IPV. There was a positive relationship between age and feelings of having sufficient knowledge of IPV, and a negative relationship between age and feelings of needing more knowledge. Finally, there was a negative relationship between being a woman and feelings of preparedness for making appropriate IPV referrals. Findings will be used as a way to recommend future education/training implementation on graduate-level coursework, in order to better prepare students for serving this client population.

The purpose of this study was to examine the comorbidity of substance use disorders and mental illness: Addressing access to dual diagnosis treatment centers and the correlation of perceived effectiveness. The research project was conducted in collaboration with California State University, San Bernardino, (CSUSB) and the Master in Social Work Program. The study used a survey designed with items that measured the participant’s perception of availability and effectiveness of dual diagnosis treatment centers. A quantitative study was conducted using a fixed choice response and data was analyzed on an interval measurement scale. Frequencies and cross tabulations were used to present participant’s answers. 86.7% of respondents perceived that they benefited from a dual diagnosis treatment center. All respondents perceived they were better equipped to manage their alcoholism after treatment, were better equipped to manage their mental illness after treatment, and better equipped to be a contributing member of society after treatment. The findings of this research may contribute to social work's knowledge of treating comorbidity by providing insight into the factors that contribute to individual's effectiveness in regards to post dual diagnosis treatment.

Social workers are needed to meet the needs of the growing aging population. Yet, there is a shortage of social work students entering the field of gerontology as opposed to child welfare, school social work, or family services. The proposed study used a qualitative research design to explore why social work students are underrepresented in areas that serve older people. A sample of 58 graduate social work students from several universities in Southern California completed open-ended questions on a scale (N = 58). Thematic analysis of the data revealed four major factors that account for the underrepresentation of social work students in gerontology. These were: (a) lack of knowledge about gerontology, (b) misconceptions about the elderly populations, (c) lack of incentives, and (d) preference for other social work areas. These findings hold major implications for theory, research, policy, and social work education.

<p>Many modern products, especially electronic goods, are protected by brominated flame retardants (BFR). Some of the most common flame retardants are polybrominated diphenylethers (PBDE), tetrabromobisphenol-A (TBBP-A) and hexabromocyclododecane (HBCD). These compounds have been found in environmental samples and shown to have physiological effects on experimental animals. This thesis considers end-of-life aspects of brominated flame retardants. When spread in the environment, these compounds may be degraded into other forms. For example, if sludge contaminated with PBDE is used as an agricultural fertilizer, the PBDE could be degraded by sunlight to species of PBDE with lower degree of bromination and, to some extent, also form polybrominated dibenzofurans (PBDF). In addition, PBDF and polybrominated dibenzo-p-dioxins (PBDD) are formed during combustion of brominated flame retardants. When waste products with brominated flame retardants are co-combusted with household waste or other chlorinated fuel, polybrominated- chlorinated dibenzo-p-dioxins (PBCDD) and polybrominated- chlorinated dibenzofurans (PBCDF)will be formed. The bromin/chlorine composition of dioxins and furans is dependent on the bromine/chlorine ratio in the fuel, but the types of brominated flame retardants that are being combusted is less important. In the studies reported here, bromine levels higher than "normal" for household waste has been used. The results show that there is a pronounced increase in total dioxin levels in fluegas when when bromine is present, implying that waste containing brominated flame retardants should only be incinerated at combustion plants with effecient air pollution control devices.</p>

<p>The disposal of combustible wastes by incineration is a controversial issue that is strongly debated by both scientists and environmental activists due to the resulting emissions of noxious compounds, including (<i>inter alia</i>) polychlorinated dibenzo-<i>p</i>-dioxins (PCDDs), dibenzofurans (PCDFs), heavy metals and acid gases like sulfur dioxide. Currently available air pollution control devices are capable of effectively cleaning flue gases, and PCDD/F emissions to air from modern municipal solid waste (MSW) incinerators are low. However, the PCDD and PCDF end up in ash fractions that, in Sweden, are usually deposited in landfills.</p><p>The European Union has recently set a maximum permitted total concentration of 15 µg TEQ/kg for PCDD/F species in waste. Fly ash from municipal solid waste (MSW) incineration containing PCDD/Fs at concentrations above this limit will have to be remediated to avoid disposing of them in landfills; an expensive and environmentally unfriendly option. Therefore, effective, reliable and cost-effective methods for degrading PCDD/F in fly ash are required, and a better understanding of the behavior of PCDDs and PCDFs during thermal treatment will be needed to develop them.</p><p>In the studies this thesis is based upon both the formation and degradation of PCDDs and PCDFs in ashes from MSW incineration were studied.</p><p>The main findings of the investigations regarding PCCD/F formation were:</p><p>- The concentrations of PCDD and PCDF in fly ash increased with reductions in the temperature in the post-combustion zone.</p><p>- The homologue profile in the ash changed when the temperature in the post-combustion zone changed.</p><p>- The final amounts of PCDD and PCDF present were affected by their rates of both formation and degradation, and the mechanisms involved differ between PCDDs and PCDFs.</p><p>The main findings from the degradation studies were:</p><p>- The chemical composition of ash has a major impact on the degradation potential of PCDD and PCDF.</p><p>- The presence of oxygen during thermal treatment can enhance the degradation of PCDD and PCDF.</p><p>- Thermal treatment is a viable option for degrading PCDD and PCDF in ashes from MSW.</p><p>- Shifts in chlorination degree occur during thermal treatment.</p><p>- Rapid heat transfer into the ash is a key factor for ensuring fast degradation of PCDD and PCDF.</p><p>- Degradation of other chlorinated organic compounds, e.g. PCB and HCB, also occurs during thermal treatment of ash.</p><p>- Reductions in levels of PCDD and PCDF were not solely due to their desorption to the gas phase.</p><p>- Differences between the behavior of 2378-substituted congeners of PCDD and PCDF and the other congeners during thermal treatment were observed.</p><p>- Differences in isomer patterns of both PCDD and PCDF were observed between the ash and gas phases after thermal treatment at both 300 and 500 oC.</p><p>Overall, the results show that the formation and degradation mechanisms of PCDDs differ substantially from those of PCDFs. Thus these groups of compounds should be separately considered in attempts to identify ways to reduce their concentrations.</p>

This dissertation investigates the possibility of producing zeolites from municipal solid waste ash, MSW ash, by using hydrothermal treatment alone and by introducing fusion at 550 °C prior to hydrothermal treatment. The study was performed at different treatment conditions where silica/aluminum ratio of 13.9 and 2.5, hydroxide concentrations of 1.5N, 2.5N and 3.5N, temperatures at 100°C and 60 °C and time at 6, 24 and 72 hours were the major variables used to study zeolites synthesis process. The possibility of forming zeolites A, P1 and X was of particular interest in the present study. Factors, mechanism and modeling of zeolite A were investigated thoroughly in the present study. Zeolite synthesis process was evaluated using X-Ray diffraction to study different formed zeolite types and their chemical composition as well as their percentages. Morphological and physical characteristics of the produced zeolitic materials were evaluated by scanning electron microscopy, and cation exchange capacity property, CEC.The findings indicate that hydrothermal process did not succeed in producing significant amounts of zeolites. Consequently, the CEC of the produced zeolitic materials were much below the available commercial zeolite materials.Fusing the ash prior to hydrothermal treatment successfully produced sodium aluminum silicates and sodium silicates precursors to zeolite A formation. Fusion followed by hydrothermal treatment yielded significant amounts of zeolite A, at maximum value of 38.8% with CEC up to 245.0 meq/100g, which is within the range of commercially available zeolites. Experimental design analysis performed on zeolite A synthesis showed that zeolite A formation was reproducible and equation of interaction between different used conditions was established. Mechanism of zeolite A formation was concluded to be solution transport mediated process that involved both gel and solution interaction rather than being pure solution reaction or pu re gel transformation process. Solution super saturation and optimum silica/aluminum ratio were the driving force for nucleation of zeolite A.

The disposal of combustible wastes by incineration is a controversial issue that is strongly debated by both scientists and environmental activists due to the resulting emissions of noxious compounds, including (inter alia) polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), heavy metals and acid gases like sulfur dioxide. Currently available air pollution control devices are capable of effectively cleaning flue gases, and PCDD/F emissions to air from modern municipal solid waste (MSW) incinerators are low. However, the PCDD and PCDF end up in ash fractions that, in Sweden, are usually deposited in landfills. The European Union has recently set a maximum permitted total concentration of 15 µg TEQ/kg for PCDD/F species in waste. Fly ash from municipal solid waste (MSW) incineration containing PCDD/Fs at concentrations above this limit will have to be remediated to avoid disposing of them in landfills; an expensive and environmentally unfriendly option. Therefore, effective, reliable and cost-effective methods for degrading PCDD/F in fly ash are required, and a better understanding of the behavior of PCDDs and PCDFs during thermal treatment will be needed to develop them. In the studies this thesis is based upon both the formation and degradation of PCDDs and PCDFs in ashes from MSW incineration were studied. The main findings of the investigations regarding PCCD/F formation were: - The concentrations of PCDD and PCDF in fly ash increased with reductions in the temperature in the post-combustion zone. - The homologue profile in the ash changed when the temperature in the post-combustion zone changed. - The final amounts of PCDD and PCDF present were affected by their rates of both formation and degradation, and the mechanisms involved differ between PCDDs and PCDFs. The main findings from the degradation studies were: - The chemical composition of ash has a major impact on the degradation potential of PCDD and PCDF. - The presence of oxygen during thermal treatment can enhance the degradation of PCDD and PCDF. - Thermal treatment is a viable option for degrading PCDD and PCDF in ashes from MSW. - Shifts in chlorination degree occur during thermal treatment. - Rapid heat transfer into the ash is a key factor for ensuring fast degradation of PCDD and PCDF. - Degradation of other chlorinated organic compounds, e.g. PCB and HCB, also occurs during thermal treatment of ash. - Reductions in levels of PCDD and PCDF were not solely due to their desorption to the gas phase. - Differences between the behavior of 2378-substituted congeners of PCDD and PCDF and the other congeners during thermal treatment were observed. - Differences in isomer patterns of both PCDD and PCDF were observed between the ash and gas phases after thermal treatment at both 300 and 500 oC. Overall, the results show that the formation and degradation mechanisms of PCDDs differ substantially from those of PCDFs. Thus these groups of compounds should be separately considered in attempts to identify ways to reduce their concentrations.

It is of great importance to acquire methods that has a sustainable solution for treatment and disposal of municipal solid waste (MSW). The volumes are constantly increasing and improper waste management, like open dumping and landfilling, causes environmental impacts such as groundwater contamination and greenhouse gas emissions. The rationalization of developing a sustainable solution implies in an improved way of utilizing waste resources as an energy source with highest possible efficiency. MSW incineration is by far the best available way to dispose the waste. One drawback of conventional MSW incineration plants is that when the energy recovery occurs in the steam power cycle configuration, the reachable efficiency is limited due to steam parameters. The corrosive problem limits the temperature of the superheated steam from the boiler which lowers the efficiency of the system. A suitable and relatively cheap option for improving the efficiency of the steam power cycle is the implementation of a hybrid dual-fuel cycle. This paper aims to assess the integration of an MSW incineration with a high quality fuel conversion device, in this case natural gas (NG) combustion cycle, in a hybrid cycle. The aforementioned hybrid dual-fuel configuration combines a gas turbine topping cycle (TC) and a steam turbine bottoming cycle (BC). The TC utilizes the high quality fuel NG, while the BC uses the lower quality fuel, MSW, and reaches a total power output of 50 MW.  Using a high-quality fuel in cogeneration can prove to be beneficial for improving and enhancing the overall plant profitability and efficiency while eliminating the corrosion problems with conventional MSW firing. The need for few interconnections between the different subunits in a parallel-fueled system allows for a wider range of operation modes and leaves room for service modes of the subunit. The hybrid dual-fuel cycle will be assessed for optimal cycle configuration and evaluated to how it compares to the sum of two separate single-fuel plants with optimal cycle configurations. Investigation of such aspects is a very important issue in order to be able to fully promote an implementation of hybrid combined cycle. The work presented herein also concentrates on investigating scenarios that include a full-load and part-load analysis in both condensing and combined heat and power (CHP) mode of operation. Through simulations and evaluation of obtained data, the results strengthens the fact that the electrical efficiency of hybrid configurations increases at least with 2% in condensing mode and 1,5% in CHP mode, comparing it to the sum of two separate single-fuel units of similar scale. The simulations show increased electrical efficiencies when running the BC in part-load and the TC in full load, with a higher NG to MSW ratio. The results also indicated that it is possible to extract more power output from the cycle by operating in CHP mode, due to more energy being utilized from the input fuel.

ABSTRACT Bioreactor landfill operation has been promoted as a means of accelerating the degradation of waste for over 30 years. Accelerating the degradation of waste enables better predictability in biogas production and reduces aftercare costs. Most bioreactor landfill trials focus on the effect of leachate recirculation on otherwise conventional landfill cells. However, there is a range of design and operational measures that can be implemented with standard landfilling machinery to further enhance degradation. This thesis explores degradation rates that can be achieved in a landfill cell, designed to maximise degradation rate, with the constraint that it be constructed by standard earthmoving equipment, the waste be crudely shredded by sheep foot compactors to expose waste, and leachate recirculation be operable by landfill personnel. The major departures of these test cells from a conventional landfill cell operation were: the cells were only 3m deep; MSW loaded into the cell was crushed and bags ruptured with a sheep foot compactor; MSW was pre-mixed prior placement with digested sludge, as a ratio such that the buffering capacity of the sludge was equivalent to an amount of NaHCO3 known to successfully buffer the digestion of packed beds of MSW (10gL-1 NaHCO3 in packed bed at field capacity moisture content plus excess leachate equal to 10% of the bed volume (Lai et al 2001); and the waste was placed rather than compacted into the cell. The thesis examines the performance of two test cells, the second only containing MSW and inoculated and buffered by sequencing with the first. These performances are compared with an exhaustive set of control digestions in 200L laboratory reactors. The laboratory reactors were packed with 50kg sub-samples of the waste used in the cells, shredded to sub 5cm size. The laboratory reactors primarily focussed on the effect of temperature on degradation rates, to identify the optimum degradation rate for this sludge and MSW mixture. The laboratory scale reactors produced 231 L and 202 L of methane per kgVS at the mesophilic temperatures of 38°C and 45°C respectively. The degradation was faster in the 45°C reactor where methane production was completely exhausted after 35 days. A laboratory reactor operated at 55°C reactor showed little degradation activity. The pH of this reactor was initially over 8.5, and ammonia inhibition was suspected. However, the reactor did not respond to pH adjustments with hydrochloric acid, and subsequent step decreases in temperature did not have an effect until 47°C, where degradation suddenly accelerated. This suggests the methanogenic consortia in the sludge could not adapt to thermophilic temperatures. This was confirmed in the 63°C reactor which acidified and did not produce methane, until leachate from this reactor was transferred to the 45°C reactor where an established methanogenic community converted the soluble COD to methane. In order to compare laboratory reactor performance with the general literature, pure cellulose was added in a fed-batch fashion to the stabilised 38°C and 47°C leach-beds. The beds were fed under starved conditions, to clearly distinguish degradation products from the cellulose from background levels. This also allowed for the estimation of biomass growth by measuring the uptake of NH4-N, as all other bio-available N sources such as protein and amino acids were reduced to NH4-N under these starved conditions. Hydrolysis rates were determined to be 0.12±0.01 d-1 and 0.14±0.026 d-1 at the 38°C and 47°C temperatures. Degradation in the two test cells was completed within a 7 month period. Temperature in the cells was maintained between 25 – 30°C by biological activity, levels that were above ambient temperatures, but below ideal mesophilic conditions. Methane composition rapidly approached 50% in both cells, and biogas flow rates were consistent with a degradation timeframe in the order of less than year. Full flow rate data was not obtained from these trials due to mechanical problems with flow meters, however vigorous gas production was evident throughout the trial by monitoring gas composition, and the ballooning effect of the top cover. To confirm the degradation rates in the test cells, samples were collected from the second test cell and digested in laboratory reactors. Methane yields were only 2.4 and 6.4 L CH4 kgVS-1 confirming virtual exhaustion of biogas potential within 7 months of sequencing this MSW cell with the first MSW:sludge test cell. This is the first systematic experimental program that places the degradation performance of a test cell in the context of the potential degradation rate achievable with fine shredding, temperature control and thorough inoculation and buffering. Economically, in cases where degradation residues are left insitu as in landfills, the degradation enhancement in the test cells would effectively yield as much benefit as enhancing the degradation rate to a two to three week timeframe typical of an anaerobic digester (Clarke 2000).