The ever-increasing population in the metropolis of Accra, Ghana resulting in con-cerns for finding lasting solutions to manage large volumes of waste produced can be tackled through composting for urban agriculture. With insanitary land filling serving as the major disposal option in the metropolis, plans to build the first ever sanitary landfill facility in the metropolis calls for measures to be taken in order to prolong the lifespan of the facility. This therefore necessitates the need to look into an alternative means of diverting organic waste from landfills. The objective of this research is to re-view the Municipal Solid Waste (MSW) management situations in Accra Metropolitan Assembly upon which an investigation is made into the various process steps involved in aerobic windrow composting and also finding out the possibility for integrating composting with urban agriculture. The study relied mainly on secondary data obtained from books, published articles, governmental documents, internet, and master thesis reports on related topics. By the help of a causal loop diagram, the interdependence of various policy actions and sys-tem elements in the waste management process are linked to illustrate the possibility of a composting programme for urban agriculture. Even though the metropolis for some time back has been operating a centralized composting facility, the facility is confirmed to be closed down due to problems ema-nating from financial inadequacy, power failure and mechanical breakdown. The study delve into the process steps in windrow composting and finally identified potentials for composting in the metropolis but however enumerated constraints ranging from human and environmental health, financial, institutional, policy directives, to public and leadership attitudes as stumbling blocks to the implementation of a centralized composting scheme. It finally concluded that the metropolis has the potentials to embark on composting for urban agriculture however, until measures are taken to overcome these constraints, implementing a centralized composting scheme in the metropolis may not be a sustainable option. It is further recommended that whiles the city authorities continue to tackle the constraints to pave way for the implementation of the program, efforts must be made in promoting small scale composting that rely on manually operated tools to help reduce organic waste loads in the municipal waste stream.

The use of renewable waste for bioenergy production is in discussion because of the concurrence to the food or animal feed. The treatment of organic waste is necessary in order to keep clean the environment. The combination of those proposals, the waste utilization and the production of renewable energy can be combined with several techniques. In Vietnam the energy demand will increase rapidly in the next years, because a lot of people do not have access to electricity. The development of power sources is limited mainly to large central power plants using hydropower and traditional fossil fuels. So in the country there exists a considerable potential for sustainable energy sources like biomass and residues. The biogas potential is large due to the high livestock population. There are more than 30 million animals in farms, mostly pigs, cattle, and water buffalo. There is a high potential for biogas utilization. Biogas production is economic in small and in big plants, so household biogas digesters are one opportunity for production of renewable energy in small villages or cities with a high livestock population. The advantage of anaerobic treatment of organic waste is the work in closed loops. The treatment of organic waste and the utilization of digested sludge from wastewater treatment plants are samples for the circulation of materials after use. The remaining materials can be used in the natural circulation process, because the nutrients such as nitrogen, phosphorous and carbon, and also trace elements remain in the digested matter. In biogas plants a huge variety of substrates can be used. The adaption of biogas technology to the special conditions of the substrates, the increase of the prices for energy, the aim to replace fossil energies with renewable energies will be forced in the next years. / Việc sử dụng chất thải có thể tái tạo được để sản xuất năng lượng sinh học là vấn đề còn đang được thảo luận vì sự cạnh tranh với thức ăn hoặc thức ăn cho động vật. Việc xử lý các chất thải hữu cơ là cần thiết để giữ sạch môi trường. Sự kết hợp của các đề xuất đó, tận dụng các chất thải và sản xuất năng lượng tái tạo có thể có thể được kết hợp với một số kỹ thuật. Ở Việt Nam, nhu cầu năng lượng sẽ tăng lên nhanh chóng trong những năm tiếp theo, bởi vì rất nhiều người vẫn chưa có điện sử dụng. Sự phát triển của các nguồn năng lượng chỉ giới hạn chủ yếu là các nhà máy điện lớn trung tâm sử dụng thủy điện và các nhiên liệu hóa thạch truyền thống. Vì vậy, trong nước tồn tại tiềm năng đáng kể cho các nguồn năng lượng bền vững như sinh khối và những nguồn khác. Tiềm năng khí sinh học lớn do quần thể động vật nuôi rất lớn. Có hơn 30 triệu động vật trong trang trại, chủ yếu là lợn, bò, trâu nước. Tiềm năng sử dụng khí sinh học rất cao. Sản xuất khí sinh học rất có hiệu quả kinh tế trong các nhà máy nhỏ và lớn, do đó, các thiết bị phản ứng tạo khí sinh học ở các hộ gia đình là một cơ hội để sản xuất năng lượng tái tạo trong các thành phố hay làng mạc nhỏ với số lượng lớn các gia súc được chăn nuôi. Ưu điểm của việc xử lý kỵ khí các chất thải hữu cơ là làm việc trong vòng khép kín. Việc xử lý các chất thải hữu cơ và sử dụng bùn phân hủy từ các nhà máy xử lý nước thải là các ví dụ cho việc tuần hoàn các vật chất sau khi sử dụng. Các vật chất còn lại có thể được sử dụng trong quá trình tuần hoàn tự nhiên, vì các chất dinh dưỡng như phốt pho, nitơ và carbon, và cả các nguyên tố vi lượng vẫn tồn tại trong nguyên liệu đã phân hủy. Trong các nhà máy khí sinh học, rất nhiều loại chất nền có thể được sử dụng. Sự cải tiến công nghệ sản xuất khí sinh học theo các điều kiện đặc biệt của các chất nền, sự gia tăng của giá năng lượng, mục đích thay thế nguồn năng lượng hóa thạch bằng năng lượng tái tạo sẽ là bắt buộc trong những năm tới.

The quick social economic development of Vietnam stimulates great demand of quality as well as quantity on transport service by the increasingly growing needs of customer for transportation. The railway passenger transport is currently still an important branch of a country’s transport system because it is safer, more eco-friendly and much more efficient in comparison to another means. However, the increasing of the number of passengers is the main causes of fast increasing waste amount from the rail service. The aim of this paper is to study how the organic waste from rail service is managed and treated today by the Vietnam railways. The paper ends with some proposal solutions for treating and disposing of organic waste by applying renewable energy technologies for climate change mitigation to protect human health and the environment. / Sự phát triển nhanh chóng của nền kinh tế Việt nam dẫn đến nhu cầu vận chuyển hành khách ngày càng tăng mạnh về số lượng cũng như chất lượng dịch vụ. Vận chuyển hành khách bằng đường sắt hiện tại ở Việt nam vẫn đóng vai trò quan trọng trong hệ thống vận tải quốc gia do lợi thế an toàn cao, thân thiện với môi trường và lợi ích cao của nó so với các phương tiện khác. Tuy nhiên sự biến động lớn của lượng hành khách đi tàu là nguyên nhân làm cho lượng rác thải từ các dịch vụ đường sắt cũng tăng mạnh. Bài báo tập trung vào nghiên cứu và làm rõ hiện trạng quản lý chất thải hữu cơ trên đường sắt Việt nam hiện nay cũng như các chiến lược nhằm xử lý chất thải hữu cơ, sử dụng công nghệ năng lượng tái tạo nhằm bảo vệ môi trường, giảm thiểu biến đổi khí hậu.

Black soldier fly larvae (BSFL) waste treatment is becoming a more sought-after organic waste treatment since it produces larvae for animal feed as well as fertilizer, the need for prediction and optimization of treatment performance increases. This study aims to predict biomass conversion efficiency (BCE) for waste going into treatment, using only the nutritional data from other studies as it could give a good performance estimation while using available data. First, macronutrient fractions, based on a normalized total weight of volatile solids (VS), were calculated from nutritional data of other studies and of this present study.  Using the results, coordinates of these samples were calculated and put on the ternary plot, revealing trends for different macronutrient compositions. To validate these trends, selected nutrient compositions were created as waste mixtures containing fish, bread and vegetable waste and then treated by BSFL. After treatment, BCE and waste reduction in both VS and wet weight basis were noted.  The results showed that a composition high in carbohydrate and low in fat content is favorable for a high BCE value while protein content remained similar across all treatments and only seemed to slightly increase BCE. Treatment A5 held the highest BCE%VS (32.6 ± 3.5) with a composition of 73%VS carbohydrates, 19%VS protein and 8%VS fat and control treatment (A0) with no fish waste held the highest BCE%WW  (21.2 ± 1.8).   When comparing with the results of the other studies used to make the trends in the ternary plot, predictions of BCE were more accurate for a composition  of  70%VS carbohydrates, 20-25%VS protein and < 8%VS fat and also for compositions with similar waste substrates, as their percental changes were similar. This suggests that it is possible to predict high BCE  values from nutritional data in a ternary plot and could be of use when optimizing larval production. / Fluglarvskompostering med den amerikanska vapensflugan (Hermetia illucens) är en avfallsbehandling för organiskt avfall som producerar larver och gödselmedel som kan används som djurfoder respektive gödselmedel.  Många studier har undersökt hur makronäringsämnen påverkar larvproduktion eller behandlingseffektiviteten och kommit till olika resultat. I dagens läge skulle det underlätta om man kunde uppskatta den högsta möjliga effektiviteten baserat på data om avfallet som redan finns utan att behöva gå igenom en längre studie först. Den här studien har som syfte att undersöka om det är möjligt att förutspå biomassomvandlings-effektivitet (BCE) från makronäringsdata tagen från andra studier i ett triangulärt diagram. I denna studie användes studierna av Lopes et al., (2020) och Isibika et al., (2021) som basdata i triangulär diagrammet.  För att validera det trender som sågs i det triangulära diagrammet utfördes tester på valda kompositioner beståendes av ansjovis, bröd och grönsaksavfall med fluglarvkompostering. För att kunna applicera makronäringsämnernas data till triangulär diagrammet, beräknades mängden protein, kolhydrater och fett som en andel av den totala mängden glödförlust (VS).  Efter behandling beräknades BCE på våtvikt (WW) och VS basis.  Resultaten tyder på att en avfallskomposition med hög halt kolhydrater och låg halt fett (70%VS kolhydrater, 20–25%VS protein and <8%VS fett) bidrog till ett högt BCE värde, där proteinhalten var snarlik i alla behandlingar och verkade ha ett litet bidrag till ett högt BCE värde. Behandlingen A5 hade det högsta BCE%VS värdet (32.6 ± 3.5) med en komposition av 73%VS kolhydrater, 19%VS protein och 8%VS fett och kontroll behandlingen A0 (utan ansjovis avfall) hade högst BCE%WW värde (21.2 ± 1.8).   Vid jämförelse mellan de andra studierna och resultaten, var uppskattningar av BCE mer precisa för en komposition med ca 70%VS kolhydrater, 20–25%VS protein and <8%VS fett och för uppskattningar baserad på data från rapporter med liknande avfallssubstrat, då deras procentuella förändringar var liknande varandra. Detta stärker hypotesen att det är möjligt att kunna förutspå högt BCE värde med hjälp av näringsdata från avfallet och skulle kunna användas för att optimera av larvproduktion.

O fornecimento de P à cana-de-açúcar é feito normalmente com fontes de alta solubilidade distribuídas de forma localizada no sulco de plantio. A solubilidade dessas fontes favorecem aos processos de adsorção/precipitação do P solúvel aos componentes do solo, reduzindo a recuperação do P aplicado. Fontes reativas podem ser uma alternativa por liberarem P de forma gradual, diminuindo as reações com os constituintes do solo e apresentarem eficiência semelhante às fontes solúveis em solos ácidos. A associação de fontes inorgânicas de P com torta de filtro deve aumentar a produtividade e melhorar a eficiência da adubação fosfatada. Esta pesquisa avaliou o efeito de fontes de fósforo solúvel e reativa, associadas à torta de filtro, no rendimento industrial e na produtividade de colmo da cana-de-açúcar e as alterações nas formas de P do solo. Foram conduzidos dois experimentos de campo para avaliar i) o comportamento de fonte solúvel e reativa na dose recomendada de 180 kg ha-1 de P2O5, aplicada a lanço, sulco e misto (50/50) e ii) avaliar as fontes utilizando metade da dose e a dose total recomendada em associação com 10 t ha-1 de torta de filtro ambos aplicadas no sulco de plantio. Houve aumento do rendimento de açúcar total recuperável (ATR), tonelada de pol por hectare (TPH) e colmos industrializáveis na cana soca da área de expansão com a adição de fertilizantes fosfatados, destacando a importância da adubação para a manutenção da produtividade em solos deficientes em P. A adição de fertilizante associado com torta de filtro aumentou o rendimento de ATR, TPH e de colmos industrializáveis e a extração de P pela cana planta na área de expansão e apenas a extração de nutrientes na área estabelecida. Em áreas que receberam sequências de adubação fosfatada o declínio da produtividade deve demorar mais tempo do que em área sem a adição de P. A fonte solúvel manteve mais P nas frações P-resina, Pi-bic e Pi-hid0.1 nas camadas 10-20 e 20-40 cm quando aplicada no sulco, enquanto a fonte reativa elevou o P-Ca na camada 0-10 cm e 10-20 cm no modo lanço ou 50/50. A fonte reativa manteve quantidades menores de P lábil do que a fonte solúvel, mas suficientes para atender a demanda da planta. As reservas de P do solo da área estabelecida foram suficientes para suprir adequadamente a cana-planta. A eficiência de recuperação do P foi baixa alcançando 20% nos dois anos na área de expansão e foi negativa na área estabelecida. O P-resina, Pi-bic e Pi-hid0.1 tenderam a serem alterados pelo ST na presença de torta e geralmente acompanhou o aumento da dose enquanto o P-HCl e o Pi-hid0.5 são alterados pelo FNR e aumenta com a dose na presença da torta com pouca influência na área estabelecida. A associação da torta de filtro com a fonte reativa pode ser uma boa opção de manejo em função da maior liberação de P pela torta no primeiro ano de aplicação e pelo importante efeito residual do fosfato reativo ao longo dos ciclos da cultura. / The supply of P to sugar cane is usually done with water soluble P sources placement in a localized way in the planting furrow. The solubility of these sources favors the adsorption/precipitation processes of the soluble P to the soil components, reducing the recovery of the applied P. Reactive sources may be an alternative for release P gradually, reducing reactions with soil constituents and presenting similar efficiency to sources soluble in acid soils. The association of inorganic sources P with filter cake should increase productivity and improve the efficiency of phosphate fertilization. This research evaluated the effect of soluble and reactive phosphorus sources, associated with filter cake, on industrial yield and yield of sugarcane stem and changes in soil P forms. Two field experiments were conducted to evaluate i) the behavior of soluble and reactive source at the recommended dose of 180 kg ha -1 of P2O5 applied broadcast, furrow and mixed (50/50) and ii) to evaluate the sources using half of the rate and the total recommended rate in association with 10 t ha -1 of filter cake both applied in the planting furrow. There was an increase in the yield of total recoverable sugar (TRS), tonne of sugar per hectare (TSH), and mill stalks in the first ratoon of the expansion area with the addition of phosphate fertilizers, emphasizing the importance of fertilization to maintain productivity in very low P content. The addition of fertilizer associated with filter cake increased the yield of TRS, TSH and mill stalks and the extraction of P by the cane plant in the expansion area and only the extraction of nutrients in the established area. In areas that received phosphate fertilization sequences the productivity decline should take longer than in the area without the addition of P. The soluble source maintained more P in the fractions P-resin, Pi-bic and Pi-hid0.1 in layers 10 -20 and 20-40 cm when applied to the furrow while the reactive source raised the P-Ca in the 0-10 cm layer and 10-20 cm in the broadcast or 50/50. The reactive source maintained smaller amounts of labile P than the soluble source, but sufficient to meet plant demand. The P reserves of the soil of the established area were enough to adequately supply the cane plant. The recovery efficiency of P was low reaching 20% in the two years in the expansion area and was negative in the established area. The P-resin, Pi-bic and Pi-hid0.1 tended to be altered by TSP in the presence of filter cake and generally accompanied the increase in rate while P-HCl and Pi-hid0.5 are altered by RP and increase with rate in the presence of the filter cake with little influence in the established area. The association of the filter cake with the reactive source can be a good management option due to the greater release of P by the filter cake in the first year of application and by the important residual effect of the reactive phosphate throughout the cycles of the culture.

O fornecimento de P à cana-de-açúcar é feito normalmente com fontes de alta solubilidade distribuídas de forma localizada no sulco de plantio. A solubilidade dessas fontes favorecem aos processos de adsorção/precipitação do P solúvel aos componentes do solo, reduzindo a recuperação do P aplicado. Fontes reativas podem ser uma alternativa por liberarem P de forma gradual, diminuindo as reações com os constituintes do solo e apresentarem eficiência semelhante às fontes solúveis em solos ácidos. A associação de fontes inorgânicas de P com torta de filtro deve aumentar a produtividade e melhorar a eficiência da adubação fosfatada. Esta pesquisa avaliou o efeito de fontes de fósforo solúvel e reativa, associadas à torta de filtro, no rendimento industrial e na produtividade de colmo da cana-de-açúcar e as alterações nas formas de P do solo. Foram conduzidos dois experimentos de campo para avaliar i) o comportamento de fonte solúvel e reativa na dose recomendada de 180 kg ha-1 de P2O5, aplicada a lanço, sulco e misto (50/50) e ii) avaliar as fontes utilizando metade da dose e a dose total recomendada em associação com 10 t ha-1 de torta de filtro ambos aplicadas no sulco de plantio. Houve aumento do rendimento de açúcar total recuperável (ATR), tonelada de pol por hectare (TPH) e colmos industrializáveis na cana soca da área de expansão com a adição de fertilizantes fosfatados, destacando a importância da adubação para a manutenção da produtividade em solos deficientes em P. A adição de fertilizante associado com torta de filtro aumentou o rendimento de ATR, TPH e de colmos industrializáveis e a extração de P pela cana planta na área de expansão e apenas a extração de nutrientes na área estabelecida. Em áreas que receberam sequências de adubação fosfatada o declínio da produtividade deve demorar mais tempo do que em área sem a adição de P. A fonte solúvel manteve mais P nas frações P-resina, Pi-bic e Pi-hid0.1 nas camadas 10-20 e 20-40 cm quando aplicada no sulco, enquanto a fonte reativa elevou o P-Ca na camada 0-10 cm e 10-20 cm no modo lanço ou 50/50. A fonte reativa manteve quantidades menores de P lábil do que a fonte solúvel, mas suficientes para atender a demanda da planta. As reservas de P do solo da área estabelecida foram suficientes para suprir adequadamente a cana-planta. A eficiência de recuperação do P foi baixa alcançando 20% nos dois anos na área de expansão e foi negativa na área estabelecida. O P-resina, Pi-bic e Pi-hid0.1 tenderam a serem alterados pelo ST na presença de torta e geralmente acompanhou o aumento da dose enquanto o P-HCl e o Pi-hid0.5 são alterados pelo FNR e aumenta com a dose na presença da torta com pouca influência na área estabelecida. A associação da torta de filtro com a fonte reativa pode ser uma boa opção de manejo em função da maior liberação de P pela torta no primeiro ano de aplicação e pelo importante efeito residual do fosfato reativo ao longo dos ciclos da cultura. / The supply of P to sugar cane is usually done with water soluble P sources placement in a localized way in the planting furrow. The solubility of these sources favors the adsorption/precipitation processes of the soluble P to the soil components, reducing the recovery of the applied P. Reactive sources may be an alternative for release P gradually, reducing reactions with soil constituents and presenting similar efficiency to sources soluble in acid soils. The association of inorganic sources P with filter cake should increase productivity and improve the efficiency of phosphate fertilization. This research evaluated the effect of soluble and reactive phosphorus sources, associated with filter cake, on industrial yield and yield of sugarcane stem and changes in soil P forms. Two field experiments were conducted to evaluate i) the behavior of soluble and reactive source at the recommended dose of 180 kg ha -1 of P2O5 applied broadcast, furrow and mixed (50/50) and ii) to evaluate the sources using half of the rate and the total recommended rate in association with 10 t ha -1 of filter cake both applied in the planting furrow. There was an increase in the yield of total recoverable sugar (TRS), tonne of sugar per hectare (TSH), and mill stalks in the first ratoon of the expansion area with the addition of phosphate fertilizers, emphasizing the importance of fertilization to maintain productivity in very low P content. The addition of fertilizer associated with filter cake increased the yield of TRS, TSH and mill stalks and the extraction of P by the cane plant in the expansion area and only the extraction of nutrients in the established area. In areas that received phosphate fertilization sequences the productivity decline should take longer than in the area without the addition of P. The soluble source maintained more P in the fractions P-resin, Pi-bic and Pi-hid0.1 in layers 10 -20 and 20-40 cm when applied to the furrow while the reactive source raised the P-Ca in the 0-10 cm layer and 10-20 cm in the broadcast or 50/50. The reactive source maintained smaller amounts of labile P than the soluble source, but sufficient to meet plant demand. The P reserves of the soil of the established area were enough to adequately supply the cane plant. The recovery efficiency of P was low reaching 20% in the two years in the expansion area and was negative in the established area. The P-resin, Pi-bic and Pi-hid0.1 tended to be altered by TSP in the presence of filter cake and generally accompanied the increase in rate while P-HCl and Pi-hid0.5 are altered by RP and increase with rate in the presence of the filter cake with little influence in the established area. The association of the filter cake with the reactive source can be a good management option due to the greater release of P by the filter cake in the first year of application and by the important residual effect of the reactive phosphate throughout the cycles of the culture.

Orientador: Mara Cristina Pessoa da Cruz / Coorientador: Manoel Evaristo Ferreira / Banca: Miguel Angelo Mutton / Banca: Glauber José de Castro Gava / Resumo: O uso de resíduos orgânicos da agroindústria de açúcar e etanol na cultura da cana-de-açúcar para fornecimento de nutrientes é comum e, ao longo dos anos, tem se mostrado benéfico. Resíduos de outras indústrias de alimentos também podem ser usados com a mesma finalidade para a cultura, desde que ela esteja nos arredores da unidade geradora. Este é o caso do lodo biológico de indústria de gelatina, resíduo com umidade alta (cerca de 98%), relação C/N baixa (1,9) e alta proporção de N-NH4 + no Ntotal. Os efeitos da utilização do lodo no solo, na produção de cana-soca e em características tecnológicas do produto foram avaliados em experimento em campo, instalado em Latossolo Vermelho argiloso, em blocos ao acaso, com cinco repetições. Os tratamentos foram cinco doses do resíduo, equivalentes a 0, 102, 204, 306 e 408 m3 ha-1, que foram calculadas para fornecer 0; 0,5; 1,0; 1,5 e 2,0 vezes a dose de N recomendada para a cultura (120 kg ha-1), com base na concentração e na taxa de mineralização do N do lodo (em torno de 80%). As doses foram parceladas em duas aplicações, uma após o corte (maio de 2010) e outra no início do período das chuvas (outubro de 2010). A aplicação de doses de lodo biológico de indústria de gelatina em solo de alta fertilidade não resultou em aumento de produção de cana-soca e nem alterou suas características tecnológicas. Dos atributos de solo avaliados, o efeito mais evidente do resíduo foi o aumento transitório do teor de Na trocável do solo, que não resultou em prejuízo para a cultura. Perdas acentuadas de N-mineral, em curto intervalo de tempo, devido às doses aplicadas e à relação C/N do resíduo, não foram detectadas. Há indicativos de que existe no sistema uma combinação de fatores favoráveis à imobilização de N (abundância de restos culturais de parte... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The use of organic wastes from sugar and ethanol agroindustry as nutrients sources for sugarcane is usual and over the years has proved to be beneficial. Others food industries wastes can also be used for the same purpose for crops, as long as they are surroundings the generating unit. This is the case of biological sludge from gelatin industry, which presents high moisture, low C/N ratio and high NH4 +-N proportion in total-N. The effects of waste application in the sugarcane ratoon yield and technological characteristics were evaluated in a field experiment, carried out in a clayey Oxisol in a randomized block design with five replicates. The treatments were five waste rates, equivalent to 0, 102, 204, 308 and 406 m3 ha-1, which were calculated to provide 0, 0.5, 1.0, 1.5 and 2.0 times the N recommendation for sugarcane (120 kg ha-1), based on the N concentration and the N mineralization rate of the waste (nearly 80%). Rates were divided in two applications: in May 2010 (after the crop) and in October 2010 (at the beginning of the rainy season). Biological sludge from gelatin industry rates has not increased sugarcane ratoon yield or changed its technological characteristics. Considering the soil attributes evaluated, the most evident waste effect was a temporary increase in exchangeable-Na, which resulted in no prejudice to the crop. Short-term mineral-N losses due to the rates and the waste C/N ratio were not detected. It seems that there is a favorable condition to the N immobilization (abundance of leaf and roots debris with medium and high C/N ratio) and unfavorable to nitrification, since there was ammonium-N form... (Complete abstract click electronic access below) / Mestre

<p>This paper reports on environmental impacts and health hazards as a result from inadequate management of organic household waste in developing countries. It gives details of water and soil contamination, air pollution and spread of diseases through expanding breeding grounds for pathogens, vectors and rodents. To manage this waste flow sustainably, decentralised composting and anaerobic digestions technologies have been studied to give an overall picture of existing appropriate technologies, including: windrow, box/bin/barrel, THM, aerated static pile, in-vessel, vermi, ARTI compact biogas digester and BARC’S NISARG-RUNA. Comparing different technologies showed that it is crucial to consider local conditions and markets when choosing which method to implement. However, the manual composting methods: windrow/box/bin/barrel, THM and vermi, are more likely to be appropriate in regard to current conditions in developing countries. A comparison between the environmental impacts of anaerobic digestion and composting did not result in a clear indication of which technology is most favourable. However, in the literature studied, biogas production showed an overall better energy balance, and composting a better result regarding nutrient recycling and xenobiotic compounds. In terms of the mitigation effect on global warming, the results varied essentially depending on the technology used and its loss of methane during the biogas production process. Finally, this paper investigates common constraints for implementation of the above-mentioned technologies, as well as recommendations for future projects. The study of general constraints revealed the need for directing attention to education, key consequences and benefits, co-operation, exchange of knowledge and bottom-up driving forces, for sustainable and successful implementation of organic household waste management practices in developing countries.</p>

This paper reports on environmental impacts and health hazards as a result from inadequate management of organic household waste in developing countries. It gives details of water and soil contamination, air pollution and spread of diseases through expanding breeding grounds for pathogens, vectors and rodents. To manage this waste flow sustainably, decentralised composting and anaerobic digestions technologies have been studied to give an overall picture of existing appropriate technologies, including: windrow, box/bin/barrel, THM, aerated static pile, in-vessel, vermi, ARTI compact biogas digester and BARC’S NISARG-RUNA. Comparing different technologies showed that it is crucial to consider local conditions and markets when choosing which method to implement. However, the manual composting methods: windrow/box/bin/barrel, THM and vermi, are more likely to be appropriate in regard to current conditions in developing countries. A comparison between the environmental impacts of anaerobic digestion and composting did not result in a clear indication of which technology is most favourable. However, in the literature studied, biogas production showed an overall better energy balance, and composting a better result regarding nutrient recycling and xenobiotic compounds. In terms of the mitigation effect on global warming, the results varied essentially depending on the technology used and its loss of methane during the biogas production process. Finally, this paper investigates common constraints for implementation of the above-mentioned technologies, as well as recommendations for future projects. The study of general constraints revealed the need for directing attention to education, key consequences and benefits, co-operation, exchange of knowledge and bottom-up driving forces, for sustainable and successful implementation of organic household waste management practices in developing countries.

There is approximately 14 million tonnes of biodegradable organic waste produced by households in the UK every year which must be treated or disposed of. The EC Directive on Landfill (1999/31IEC), is likely to lead to an increase in compo sting and anaerobic digestion as methods to treat the waste stream diverted from landfill. Householders play an important role in separating their waste, which, if not performed efficiently can lead to contamination of the organic waste stream, and hence the compost product. A survey is used to determine the attitude and behaviour of householders to waste issues. It was found that residents in the less affluent area were less likely to home compost and had a less favourable attitude towards environmental activities than residents in the affluent area. A comparison of compost from centralised composting schemes treating different organic waste streams found that compost derived from household waste was of a slightly poorer quality than that obtained from gardens/parks waste. As more waste is recycled as compost, it is becoming increasingly important to find alternative uses for compost. Leachability data are used to determine the environmental availability of Cd, Cu, Pb, and Zn contained in natural compost. Batch sorption data are used to determine uptake of additional Cd, Cu, Pb, and Zn by compost and assess its potential use in remediation work, as an alternative to natural materials such as peat. The relative binding of these additional metals to compost is found to be in the order Pb>Cu≈Cd>Zn. The sorption of metals on compost takes place, at least in part, by exchange of calcium bound to the compost and there is evidence that the sorption occurs in both the humic and non-humic sites in the compost. The use of compost to bind metals in remediation work is discussed.