The extensive use of nanoparticles (NPs) has started receiving increased attention because of the knowledge gaps regarding their fate in the environment and the possible impact on the environment and human health. The production of silver nanoparticles (AgNPs) and titanium dioxide nanoparticles (TiO2-NPs) is increasing and it is expected that, due to their great number of applications, their concentration in waste streams will increase in the future. The presence of NPs in waste streams may affect the treatment process (e.g., composting) and, if they are not successfully removed from the waste streams, their presence in the treated waste (e.g., compost) may present an environmental risk. Composting of the biodegradable fractions of municipal solid waste (MSW) is a widely used waste management practice, mainly because it is a cost-effective treatment technology and the final product (i.e., compost) presents several benefits to the environment, particularly as a soil conditioner. The overall aim of this thesis is to assess the effect of Ag-TiO2NPs and AgNPs that may be present in the biodegradable fractions of municipal solid waste on composting and subsequent soil application of compost. For that purpose in-vessel composting of artificial municipal solid waste contaminated with commercial nanoparticles was investigated at laboratory scale, simulating a range of relevant concentration levels. Subsequently, the fate of NPs present in mature compost use as a top-layer soil conditioner was investigated using a column approach at laboratory scale. The toxicity effect of NPs present mature compost on plant growth was further investigated. The impact of NPs during composting was assessed by monitoring the temporal dynamics of organic matter (OM) using Excitation Emission Matrix (EEM) fluorescence spectroscopy. The fate of NPs following application of contaminated mature compost as a top-soil conditioner and potential release to groundwater was investigated using a column leaching experiment while the phytotoxicity of mature compost contaminated with NPs was assessed using a seed germination bioassay. Finally, to investigate further possible environmental impacts due to the application of mature compost contaminated with NPs to soils, a Life Cycle Assessment (LCA) was conducted. The impact of commercial Ag-TiO2 NPs and AgNPs on the in-vessel composting of biodegradable municipal solid waste was investigated over 21 days, using initial concentrations of 0, 5, 10, 20 and 50 mg Ag / kg of OM. Microbial activity was inhibited in the biodegradable waste reactors using 2% NaN3 to evaluate abiotic losses. Physicochemical parameters such as pH, ash content, weight loss, and the formation of humic substances (HS) were determined after 0, 4, 7, 14 and 21 days of composting and after a maturation phase. The results indicated that the presence of 2% NaN3 in biodegradable MSW inhibited effectively the microbial activity during the first week of composting. The microbial population was activated during the second week of composting but the decomposition rate was so low that did not result in the formation of humic substances (HS) following 21 days of composting when 2% NaN3 was used. Both treatments, using Ag-TiO2-NPs and AgNPs, did not show any inhibition of the decomposition process for all the tested concentrations and EEM peaks shifted towards the HS region during in-vessel composting. Higher inorganic carbon removal resulted from NP-contaminated compost with higher NP concentrations. This may indicate that the formation of humins was higher for non-contaminated compost and decreased as the NP concentration in waste increased. The shift of the peaks towards the HS region during composting for all the treatments suggested that NPs did not have an effect on humification and therefore on compost stability. The leaching properties of the NP-contaminated compost were investigated using a column leaching test. Five samples of leachate, of 50 mL each, were collected. The highest concentrations of HS were observed in the first two leaching samples. The leaching results suggested that only a low percentage of the total NPs (in weight) in compost, up to ca. 5% for Ag and up to ca. 15% for Ti, leached out from the columns, which was assumed the amount that potentially could leach to the environment. These results suggested that NPs will mainly accumulate in soils’ top layers following application of compost contaminated with NP. The phytotoxicity of NP-contaminated compost was assessed using a seed germination bioassay and the germination index was then calculated. The results indicated that the NP-contaminated compost did not present any toxic effects to cress germination. The possible environmental impacts due to the NP-contaminated compost application to soils were investigated by conducting a comparative LCA study. The LCA study indicated that the effects of NP-contaminated compost to human health and ecosystems endpoint categories increased due to the presence of NPs. The risks are associated with terrestrial ecotoxicity and human toxicity midpoint categories and are mainly attributed to the accumulation of Ag to soils.

As municipalities in the developing world are struggling to deal with the ever-increasing rate of residential trash generation, many have embraced the practice of diverting organic waste to composting plants. However, because most models for implanting new Solid Waste Management (SWM) programs have emerged from the experiences of municipalities in the industrialized world, they often gloss over the particular social, cultural and economic contexts that make SWM programming particularly challenging in the developing world. In Mexico City, the absence of curbside collection, and a trash workforce comprised of both formal and informal trash collectors, have created unique challenges for the municipality’s composting program that was initiated in 2004. This report attempts to highlight that the limited success of the program thus far might be rooted in the program’s design, which has largely ignored the needs of the trash workers who are largely held responsible for its implementation. / text

<p>In the coming years, organic food waste will be collected in the region of Gästrikland, Sweden. The collection is planned to cover the entire region by the end of year 2007. To start with, smaller amounts are being collected and transported to a central composting plant in Sala. However, a central composting plant in the region of Gästrikland is projected.</p><p>The objective of this thesis is to evaluate a number of possible methods for composting of organic food wastes regarding their environmental impacts and localization.</p><p>There are four scenarios for future composting of organic waste that have been evaluated. There are two that consist of membrane composting, either in Sala or in the region of Gästrikland. The other two scenarios consist of tunnel composting in the region of Gästrikland with two possible placements.</p><p>The result from the systems analysis shows a lower environmental impact when using tunnel composting, compared to membrane composting. As the tunnel compost uses technologies for treating the compost gas, the amount of substances that can contribute to acidification and eutrophication is considerably lowered. However, the use of electricity is higher since the automatic process demands a greater electricity input. At a membrane composting plant, vehicles are being used to move compost material. The combustion of diesel oil gives rise to gases that increase the global warming. According to future legislations, tunnel composting gives an easier control of the emissions and optimization of the compost process.</p> / <p>Under de kommande åren kommer organiskt avfall samlas in från Gästrikeregionen för att komposteras. Insamlingen beräknas täcka hela regionen vid årsskiftet 2007/2008. Till en början samlas mindre mängder in och transporteras till en komposterings-anläggning i Sala. I framtiden planeras dock en komposteringsanläggning i Gästrikeregionen.</p><p>Syftet med examensarbetet var att utvärdera ett antal tänkbara komposterings-anläggningar för matavfallet med avseende på deras miljöpåverkan, samt deras lokalisering.</p><p>Fyra framtidsscenarier för kompostering av det organiska avfallet har utvärderats. Två innefattar membrankompostering, antingen i Sala eller i regionen. De följande två scenarierna innebär tunnelkompostering i Gästrikeregionen, vid Forsbacka avfallsdeponi eller vid ett område söder om Forsbacka.</p><p>Resultaten från systemanalysen påvisar en lägre miljöpåverkan från en tunnelkompost än från en membrankompost. På grund av en högre rening av kompostgasen förhindras övergödande och försurande ämnen att släppas ut. Tunnelkompostering innebär dock en högre elförbrukning jämfört med membrankompostering eftersom stora delar av anläggningen är automatiserad. Membrankompostering förbrukar däremot mer diesel än tunnelkompostering vid förflyttning av kompostmaterialet, vilket ger högre utsläpp av framförallt klimatpåverkande gaser. Generellt kan sägas att tunnelkompostering innebär att anläggningens emissioner lättare kan kontrolleras. Dessutom kan styrningen av kompostprocessen lättare förändras i enlighet med framtida krav och bestämmelser.</p>

A matéria orgânica (MO) encontrada no solo pode ser dividida em dois compartimentos, o primeiro é composto pela fração não humificada, representada pelos compostos orgânicos com categoria bioquímica definida (proteínas, açúcares, ceras, graxas, resinas) e o segundo é formado pelas substâncias húmicas (SH), produtos da intensa transformação dos resíduos orgânicos pela biomassa e polimerização dos compostos orgânicos. A MO funciona como um reservatório de nutrientes do solo, sendo então responsável pela fertilidade deste. O cultivo intensivo tende a reduzir a quantidade de MO. A utilização de fertilizantes orgânicos, também chamados de biofertilizantes, é considerada uma alternativa sustentável de recuperar a fertilidade do solo, pois além de repor adequadamente os nutrientes perdidos ainda reutiliza resíduos orgânicos que se dispensados na natureza causariam impactos ambientais negativos. Neste trabalho foram obtidos dois biofertilizantes de esterco bovino, utilizando os processos de vermicompostagem e o de compostagem sólida acrescentada de microrganismos provenientes do produto comercial denominado Microgeo&reg. Para fins de caracterização e comparação, foram realizadas análises físico-químicas nesses biofertilizantes, cujos resultados demonstraram que ambos se encontram dentro dos parâmetros estabelecidos pelo Ministério de Agricultura Pecuária e Abastecimento (MAPA), para a comercialização de fertilizantes orgânicos e que houve uma maior incorporação de nutrientes no esterco após a realização dos dois processos. Para a determinação do grau de humificação dos biofertilizantes, foram utilizadas as técnicas de espectroscopia de fotoacústica e ultravioleta - visível, que apresentaram a mesma tendência de absorção, tendo absorção máxima, próximo a 300nm, e a técnica de espectroscopia de infravermelho que apresentou bandas de absorção tipicamente encontradas em estruturas de ácidos húmicos, para ambos os biofertilizantes. Foram realizados também, testes de germinação com os biofertilizantes obtidos, utilizando sementes de alface, que apresentaram boa germinação e bom crescimento de biomassa para os dois biofertilizantes. Concluiu-se então com este trabalho que os dois produtos obtidos apresentam características similares e podem ser utilizados com eficiência na recuperação da fertilidade de solos. / The organic matter (OM) in the soil can be divided into two compartments. The first is composed of non humified fraction, represented by the organic compounds with defined biochemical category (proteins, sugars, waxes, greases, resins) and the second compartment is formed by humic substances, which are products of intense transformation of the organic matter and biomass by polymerization of the organic compounds. The OM acts as a reservoir of soil nutrients and it is responsible for soil fertility. The intensive agriculture tends to reduce this amount of OM. The use of organic fertilizers, also called biofertilizers, is considered a sustainable alternative to restore soil fertility, as well as restore lost nutrients properly by reusing organic waste which if released in the environment could cause negative environmental impacts. In this work two biofertilizers were obtained from cattle manure, using the vermicomposting and solid composting processes. In the solid composting process it was added microorganisms from the commercial product called Microgeo&reg. For purposes of characterization and comparison, physical-chemical analysis were performed in these biofertilizers, showing that both are within the parameters established by the Ministry of Agriculture Livestock and Supply, for the marketing of organic fertilizers and a greater incorporation of nutrients in the cattle manure after the completion of the two processes occurs. To determine the degrees of humification of the produced biofertilizers both photoacoustic and ultraviolet - visible spectroscopic techniques were used, showing the same trend of absorption and maximum absorption near 300 nm. The infrared spectroscopy which showed absorption bands typically found in structures of humic acids for both fertilizers was also used. The germination tests were performed using lettuce seeds planted in soil mixed with the biofertilizers. The results pointed out to a good germination and growth of biomass for two biofertilizers. The conclusion of this work was that both biofertilizers have similar characteristics and both can be used effectively in the recovery of soil fertility.

A matéria orgânica (MO) encontrada no solo pode ser dividida em dois compartimentos, o primeiro é composto pela fração não humificada, representada pelos compostos orgânicos com categoria bioquímica definida (proteínas, açúcares, ceras, graxas, resinas) e o segundo é formado pelas substâncias húmicas (SH), produtos da intensa transformação dos resíduos orgânicos pela biomassa e polimerização dos compostos orgânicos. A MO funciona como um reservatório de nutrientes do solo, sendo então responsável pela fertilidade deste. O cultivo intensivo tende a reduzir a quantidade de MO. A utilização de fertilizantes orgânicos, também chamados de biofertilizantes, é considerada uma alternativa sustentável de recuperar a fertilidade do solo, pois além de repor adequadamente os nutrientes perdidos ainda reutiliza resíduos orgânicos que se dispensados na natureza causariam impactos ambientais negativos. Neste trabalho foram obtidos dois biofertilizantes de esterco bovino, utilizando os processos de vermicompostagem e o de compostagem sólida acrescentada de microrganismos provenientes do produto comercial denominado Microgeo&reg. Para fins de caracterização e comparação, foram realizadas análises físico-químicas nesses biofertilizantes, cujos resultados demonstraram que ambos se encontram dentro dos parâmetros estabelecidos pelo Ministério de Agricultura Pecuária e Abastecimento (MAPA), para a comercialização de fertilizantes orgânicos e que houve uma maior incorporação de nutrientes no esterco após a realização dos dois processos. Para a determinação do grau de humificação dos biofertilizantes, foram utilizadas as técnicas de espectroscopia de fotoacústica e ultravioleta - visível, que apresentaram a mesma tendência de absorção, tendo absorção máxima, próximo a 300nm, e a técnica de espectroscopia de infravermelho que apresentou bandas de absorção tipicamente encontradas em estruturas de ácidos húmicos, para ambos os biofertilizantes. Foram realizados também, testes de germinação com os biofertilizantes obtidos, utilizando sementes de alface, que apresentaram boa germinação e bom crescimento de biomassa para os dois biofertilizantes. Concluiu-se então com este trabalho que os dois produtos obtidos apresentam características similares e podem ser utilizados com eficiência na recuperação da fertilidade de solos. / The organic matter (OM) in the soil can be divided into two compartments. The first is composed of non humified fraction, represented by the organic compounds with defined biochemical category (proteins, sugars, waxes, greases, resins) and the second compartment is formed by humic substances, which are products of intense transformation of the organic matter and biomass by polymerization of the organic compounds. The OM acts as a reservoir of soil nutrients and it is responsible for soil fertility. The intensive agriculture tends to reduce this amount of OM. The use of organic fertilizers, also called biofertilizers, is considered a sustainable alternative to restore soil fertility, as well as restore lost nutrients properly by reusing organic waste which if released in the environment could cause negative environmental impacts. In this work two biofertilizers were obtained from cattle manure, using the vermicomposting and solid composting processes. In the solid composting process it was added microorganisms from the commercial product called Microgeo&reg. For purposes of characterization and comparison, physical-chemical analysis were performed in these biofertilizers, showing that both are within the parameters established by the Ministry of Agriculture Livestock and Supply, for the marketing of organic fertilizers and a greater incorporation of nutrients in the cattle manure after the completion of the two processes occurs. To determine the degrees of humification of the produced biofertilizers both photoacoustic and ultraviolet - visible spectroscopic techniques were used, showing the same trend of absorption and maximum absorption near 300 nm. The infrared spectroscopy which showed absorption bands typically found in structures of humic acids for both fertilizers was also used. The germination tests were performed using lettuce seeds planted in soil mixed with the biofertilizers. The results pointed out to a good germination and growth of biomass for two biofertilizers. The conclusion of this work was that both biofertilizers have similar characteristics and both can be used effectively in the recovery of soil fertility.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2018-09-27T18:16:03Z No. of bitstreams: 1 2017 - Claudete Martins da Silva Pereira.pdf: 1419427 bytes, checksum: e45ce15f8c49fe9280e4eb8f4f21ca53 (MD5) / Made available in DSpace on 2018-09-27T18:16:03Z (GMT). No. of bitstreams: 1 2017 - Claudete Martins da Silva Pereira.pdf: 1419427 bytes, checksum: e45ce15f8c49fe9280e4eb8f4f21ca53 (MD5) Previous issue date: 2017-03-30 / The soil?s fertility and nutrient cycling are essential for agricultural production. Many organisms play a key role in the decomposition of organic matter present in nature. Among these organisms, more attention and research should be directed to the coprophagous insects. They transform agricultural residues in material rich in nutrients. Coleoptera families act in the fragmentation of decomposing organic matter (vegetal remains, rotten wood, straw, manure, among others), participating in the cycling of nutrients, but little is known about the humus produced by other species of the fauna of the soil beyond the earthworms. The objective of this work was to study compost from rabbit manure processed by beetle larvae under controlled conditions, and to analyze the potential of usage of this compost as substrate for lettuce seedlings production. To reach this goal, the study was accomplished in Embrapa Agrobiologia, Serop?dica (RJ), and it was divided in two phases. In the first chapter, the rabbit manure by beetle larvae and earthworms were incubated, aiming the compost production. During the course of the composting process, samples were taken at 0, 30, 60 and 90 days of incubation. In these samples the variables analyzed were: electrical conductivity (EC); pH; contents of N, P, K, Ca and Mg; and humic substances. In the second chapter the rabbit manure compost produced were evaluated as substrates for lettuce seedlings production. The following characteristics were evaluated: germination percentage, aerial part's height, number of leaves, production of fresh mass of aerial part and of the root, root volume and clod stability. The results indicated that the substrate of the cuniculture residue compost processed by cetoniinae larvae was as efficient as the substrate from vermicomposting, and the substrate commonly used in the experimental research site (Fazendinha km 47) for production of lettuce seedlings. / A fertilidade do solo e a ciclagem de nutrientes s?o fundamentais para a produ??o agr?cola. Muitos organismos exercem papel fundamental na decomposi??o da mat?ria org?nica presente na natureza. Dentre esses organismos, maior aten??o e pesquisa devem ser direcionadas aos insetos copr?fagos, por tamb?m transformarem res?duos da agropecu?ria, em material rico em nutrientes. As fam?lias de cole?pteros atuam na fragmenta??o da mat?ria org?nica em decomposi??o (restos vegetais, madeira podre, palha, estercos, entre outros), participando da ciclagem de nutrientes, por?m, pouco se conhece sobre o h?mus produzido por outras esp?cies da fauna do solo que n?o sejam as minhocas. O objetivo deste trabalho foi estudar a compostagem de esterco de coelho por larvas de besouro em condi??es controladas e analisar o potencial de uso do composto produzido como substrato para produ??o de mudas de alface. Visando alcan?ar este objetivo, este trabalho foi realizado na Embrapa Agrobiologia em Serop?dica, RJ, sendo dividido em duas etapas. No cap?tulo I, foi realizada a incuba??o de esterco de coelho por larvas de besouro e por minhocas, visando a produ??o do composto. Durante o decorrer do processo de compostagem, amostras foram coletadas aos 0, 30, 60 e 90 dias de incuba??o. Nessas amostras foram analisadas as seguintes vari?veis, condutividade el?trica (CE), pH, teores de N, P, K, Ca e Mg e subst?ncias h?micas. No cap?tulo 2, os compostos de esterco de coelho produzidos foram avaliados como substratos para a produ??o de mudas de alface. As seguintes caracter?sticas foram avaliadas: porcentagem de germina??o, altura da parte a?rea, n?mero de folhas, produ??o de massa fresca da parte a?rea e da raiz, volume de raiz e estabilidade do torr?o. Os resultados obtidos indicam que o substrato oriundo da compostagem de res?duos da cunicultura, realizada por larvas de cetoniinae, ? t?o eficiente quanto o substrato obtido atrav?s da vermicompostagem e o substrato comumente utilizado na Fazendinha km 47 para a produ??o de mudas de alface.

Traditional measures used in the composting industry for ammonia and odor emissions control are those involving collection and treatment such as thermal oxidation, adsorption, wet scrubbing and biofiltration. However, these methods do not address the source of the odor generation problem. The primary objective of this thesis research was to develop preventive means to minimize ammonia and odor emissions, and maximize nitrogen conservation to increase the agronomic value of compost. Laboratory-scale experiments were performed to examine the effectiveness of various technologies to minimize these emissions during the active phase of composting. These techniques included precipitating ammonium into struvite in composting matrix before it release to outside environment; the use of chemical and biological additives in the form of yeast, zeolite and alum; and the manipulation of key operational parameters during the composting process. The fact that struvite crystals were formed in manure composting media, as verified by both XRD and SEM-EDS analyses, represents novel findings from this study. This technique was able to reduce ammonia emission by 40-84%, while nitrogen content in the finished compost was increased by 37-105%. The application of yeast and zeolite with dosages of 5-10% enhanced the thermal performance of composting and the degree of degradation, and ammonia emission was reduced by up to 50%. Alum was found to be the most effective additive for both ammonia and odor emission control; ammonia emission decreased by 45-90% depending on the dosage, and odor emission assessed via an dynamic dilution olfactometer was reduced by 44% with dosages above 2.5%. This study reaffirmed that aeration is the most influential factor to odor emission. An optimal airflow rate for odor control would be 0.6 L/min.kg dry matter with an intermittent aeration system. Quantitative relationships between odor emission and key operational parameters were determined, which would enable “best management practices” to be devised and implemented for composting. An empirical odor predictive model was developed to provide a simple and direct means for simulation of composting odor emissions. The effects of operating conditions were incorporated into the model with multiplicative algorithm and linearization approximation approach. The model was validated with experimental observations.

China currently produces the largest quantity of municipal solid waste (MSW) in the world at 190, 000, 000 metric tones (World Bank 2005). China faces the continuing challenge of increased waste generation due to population growth, increased income, and increased urbanization. As part of environmental protection initiatives, the central government has issued many policy commitments at the national level to address waste management. In concurrence with the national objectives of addressing the problem of waste management, Hainan province has developed an integrated waste management plan that it hopes to implement by 2020 (The Hainan City Environment and Sanitary Association, in association with Hua Zhong University of Science and Technology of Environmental Science and Engineering, 2005). Organic waste, which accounts for a significant proportion of the waste stream in China, poses both challenges and opportunities in terms of disposal and recovery. While the final disposal of organics may present significant challenges, recovery of organic waste through composting is one alternative. Composting is widely recognized as an effective method of turning organic waste into a useful product. Nevertheless, the implementation of composting as part of a Municipal Solid Waste Management (MSWM) strategy faces challenges. Broadly, these challenges include administrative/policy, human acceptance and participation, management, technological and logistical, and marketing as well as composting process, source separation, contamination, quality of the final product, appropriate composting technologies and final demand and distribution of the final product (Schubeler et al. 1996, Hoornweg et al. 1999). This thesis uses a case study approach in implementing a composting pilot project in cooperation with the local and provincial government in Baisha Hainan China. Labor intensive, low technological, windrow composting is used so as to assess the challenges and potential of implementing composting as part of a municipal solid waste management strategy in Baisha Hainan China. The research uses a participatory action research approach incorporating research methods such as participant observation, key informant interviews (n=122), and rapid rural appraisals. The research objectives are to understand the current waste management system, understand how implementing composting affects the waste management system entails, understand the barriers to implementation, understand the implications: impact of implementation, potential, and finally to propose recommendations on how to implement composting. The research identified seven necessary key factors that if not given sufficient attention could potentially jeopardize the successful implementation and operation of composting: governmental support must be present, funds must be made available since operating cost of the waste management system will increase, best practices for composting must be established, training for waste workers must be provided, a market (or end use) for the final product must be established, NIMBY needs to be addressed, source separation should be applied.

In the coming years, organic food waste will be collected in the region of Gästrikland, Sweden. The collection is planned to cover the entire region by the end of year 2007. To start with, smaller amounts are being collected and transported to a central composting plant in Sala. However, a central composting plant in the region of Gästrikland is projected. The objective of this thesis is to evaluate a number of possible methods for composting of organic food wastes regarding their environmental impacts and localization. There are four scenarios for future composting of organic waste that have been evaluated. There are two that consist of membrane composting, either in Sala or in the region of Gästrikland. The other two scenarios consist of tunnel composting in the region of Gästrikland with two possible placements. The result from the systems analysis shows a lower environmental impact when using tunnel composting, compared to membrane composting. As the tunnel compost uses technologies for treating the compost gas, the amount of substances that can contribute to acidification and eutrophication is considerably lowered. However, the use of electricity is higher since the automatic process demands a greater electricity input. At a membrane composting plant, vehicles are being used to move compost material. The combustion of diesel oil gives rise to gases that increase the global warming. According to future legislations, tunnel composting gives an easier control of the emissions and optimization of the compost process. / Under de kommande åren kommer organiskt avfall samlas in från Gästrikeregionen för att komposteras. Insamlingen beräknas täcka hela regionen vid årsskiftet 2007/2008. Till en början samlas mindre mängder in och transporteras till en komposterings-anläggning i Sala. I framtiden planeras dock en komposteringsanläggning i Gästrikeregionen. Syftet med examensarbetet var att utvärdera ett antal tänkbara komposterings-anläggningar för matavfallet med avseende på deras miljöpåverkan, samt deras lokalisering. Fyra framtidsscenarier för kompostering av det organiska avfallet har utvärderats. Två innefattar membrankompostering, antingen i Sala eller i regionen. De följande två scenarierna innebär tunnelkompostering i Gästrikeregionen, vid Forsbacka avfallsdeponi eller vid ett område söder om Forsbacka. Resultaten från systemanalysen påvisar en lägre miljöpåverkan från en tunnelkompost än från en membrankompost. På grund av en högre rening av kompostgasen förhindras övergödande och försurande ämnen att släppas ut. Tunnelkompostering innebär dock en högre elförbrukning jämfört med membrankompostering eftersom stora delar av anläggningen är automatiserad. Membrankompostering förbrukar däremot mer diesel än tunnelkompostering vid förflyttning av kompostmaterialet, vilket ger högre utsläpp av framförallt klimatpåverkande gaser. Generellt kan sägas att tunnelkompostering innebär att anläggningens emissioner lättare kan kontrolleras. Dessutom kan styrningen av kompostprocessen lättare förändras i enlighet med framtida krav och bestämmelser.

China currently produces the largest quantity of municipal solid waste (MSW) in the world at 190, 000, 000 metric tones (World Bank 2005). China faces the continuing challenge of increased waste generation due to population growth, increased income, and increased urbanization. As part of environmental protection initiatives, the central government has issued many policy commitments at the national level to address waste management. In concurrence with the national objectives of addressing the problem of waste management, Hainan province has developed an integrated waste management plan that it hopes to implement by 2020 (The Hainan City Environment and Sanitary Association, in association with Hua Zhong University of Science and Technology of Environmental Science and Engineering, 2005). Organic waste, which accounts for a significant proportion of the waste stream in China, poses both challenges and opportunities in terms of disposal and recovery. While the final disposal of organics may present significant challenges, recovery of organic waste through composting is one alternative. Composting is widely recognized as an effective method of turning organic waste into a useful product. Nevertheless, the implementation of composting as part of a Municipal Solid Waste Management (MSWM) strategy faces challenges. Broadly, these challenges include administrative/policy, human acceptance and participation, management, technological and logistical, and marketing as well as composting process, source separation, contamination, quality of the final product, appropriate composting technologies and final demand and distribution of the final product (Schubeler et al. 1996, Hoornweg et al. 1999). This thesis uses a case study approach in implementing a composting pilot project in cooperation with the local and provincial government in Baisha Hainan China. Labor intensive, low technological, windrow composting is used so as to assess the challenges and potential of implementing composting as part of a municipal solid waste management strategy in Baisha Hainan China. The research uses a participatory action research approach incorporating research methods such as participant observation, key informant interviews (n=122), and rapid rural appraisals. The research objectives are to understand the current waste management system, understand how implementing composting affects the waste management system entails, understand the barriers to implementation, understand the implications: impact of implementation, potential, and finally to propose recommendations on how to implement composting. The research identified seven necessary key factors that if not given sufficient attention could potentially jeopardize the successful implementation and operation of composting: governmental support must be present, funds must be made available since operating cost of the waste management system will increase, best practices for composting must be established, training for waste workers must be provided, a market (or end use) for the final product must be established, NIMBY needs to be addressed, source separation should be applied.