Littérature scientifique sur le sujet « Wasteward »

Communal facilities performance improvement is a critical component of the overall issue of improving the citizens’ quality of life. Recreation schemes for drain-water utilization should provide not only for a primary treatment, but also for finer and more efficient methods of neutralization and sanitation. The authors of the article focus on the technologies of processing the bioslime obtained from the municipal wastewarer.

The results of sewage treatment from nickel ions are given in the article. The relevance of the studies is determined by the expansion of the spectrum of effective sorbents-reagents as a result of the use of industrial wastes. Mineralogical and component compositions of abrasive waste are studied. The process of sorption and desorption of nickel ions on the wastewas studied by theconstruction isotherm method and a mixed character of sorption processes with a predominance of physical interactions was established.

In order to effectively resolve pollution issue of water quenched slag and its comprehensive use or second use of materials, the water quenched slag filter material is developed using water quenched slag with the addition of adhesion-increasing agent and porogen by commingle, pelletizing and curing. Experimental results indicate that water quenched slag filter material is used as filter medium in biological aerated filter for wastewater treatment,and the removal rate of COD, NH3-N comes up to 84.62%,90.20% respectively. The filter material is much more predominant and possesses a much wider application prospect in the treatment of wastewate.

In this study, the V-doped TiO2 was synthesized by sol-gel method and we evaluate the photocatalytic degrading efficiency of V-TiO2 complexes on azo dye wastewater under irradiation with visible light (λ= 419 nm). The results showed that the Anatase structure and nano size of V-TiO2 complexs were formed and they had better photo-response to visible light than pure TiO2. The efficiency of decoloriztion or destruction efficiency was less than 6 % using TiO2 alone but efficiency of 0.10VT-I was up to 90% after irradiated with visible light for 240 min. These evidences also reveal that the system of V-TiO2 complexes can directly utilize the sunlight and can be used to treat organic pollutants in the practical wastewate treatment factories.

Wastewater can be an energy source and not a problem. This study investigates whether rapidly emerging bioelectrochemical technologies can go beyond working in a laboratory under controlled temperatures with simple substrates and actually become a realistic option for a new generation of sustainable wastewater treatment plants. The actual amount of energy available in the wastewater is established using a new methodology. The energy is found to be considerably higher than the previous measurement, or estimates based on the chemical oxygen demand with a domestic wastewater sample containing 17.8 kJ/gCOD and a mixed wastewater containing 28.7 kJ/gCOD. With the energy content established the use of bioelectrochemical systems is examined comparing real wastewater to the ‘model’ substrate of acetate. The abundance of exoelectrogenic bacteria within the sample, and the acclimation of these systems is examined through the use of most probable number experiments. It is found that there may be as few as 10-20 exoelectrogens per 100 mL. The impact of temperature, substrate and inoculum source on performance and community structure is analysed using pyrosequencing. Substrate is found to have a critical role, with greater diversity in acetate fed systems than the wastewater fed ones, indicating that something other than complexity is driving diversity. Laboratory scale microbial electrolysis cells are operated in batch mode fail when fed wastewater, whilst acetate fed reactors continue working, the reasons for this are examined. However a pilot scale, continuous flow microbial electrolysis cell is built and tested at a domestic wastewater treatment facility. Contrary to the laboratory reactors, this continues to operate after 3 months, and has achieved 70% electrical energy recovery, and an average 30% COD removal. This study concludes that wastewater is a very complex but valuable resource, and that the biological systems required to extract this resource are equally complex. Through the work conducted here a greater understanding and confidence in the ability of these systems to treat wastewater sustainably has been gained.

Thesis: Ph. D. in Urban and Regional Planning, Massachusetts Institute of Technology, Department of Urban Studies and Planning, 2017.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 278-306).
For many people, recycling is a habitual environmental action. In recent years, however, critics have shown that municipal recycling programs are not always environmentally beneficial. Municipal waste management programs are, nevertheless, a key lever through which cities can influence material consumption, which is a driver of ecological overshoot and greenhouse gas emissions. Through transformation of municipal waste management, including and beyond the adoption of expanded recycling programs, cities can potentially reduce their environmental footprints. In the U.S., some cities seem to have been able to do this, and while most have not. This dissertation asks why. Specifically, I ask if Seattle, a city known for its progressive waste programming, is substantially different from Boston, a city with relatively average waste and recycling programs-beyond the superficial metric of diversion rate. If so, how? Further, what enabled Seattle to fundamentally change its complex, socio-technical waste system? I find that the cities do differ meaningfully. Seattle's high diversion rate is a signal of deeper institutional changes to its waste system that position the city in opposition to dominant regimes of waste generation and management in the U.S. To compare the two cities, I use a combination of grounded theory and process tracing techniques to analyze archival data, interviews with system actors, and local press from 1980 to 2016. Building on Zsuzsa's Gille's theory of waste regimes, I argue that the U.S. is dominated by a "weak recycling waste regime" that prioritizes hygiene, sanitation, and efficiency, while allowing limited post-consumer recycling of a few materials-paper, glass, metal, and plastic-regardless of the environmental efficacy of doing so. This regime is a product of the sanitary engineering discipline, the demands of a consumption-driven capitalist economy, and the influence of manufacturers seeking to avoid more invasive environmental regulation; it depends on rapid disposal and relatively invisible garbage. Boston operates well within the parameters of this regime. Seattle, on the other hand, has fundamentally reoriented its waste system towards goals of waste reduction and resource stewardship. Seattle and Boston's waste systems differ in many ways, but the key difference lies not in organizational or infrastructural distinction, but in how each city responded to a disposal crisis in the early 1980s. Seattle's crisis led to a wide open public dialogue about garbage, through which the problem of waste in the city was redefined. Traditional problem frames of sanitation and disposal gave way to new problem frames about the value of the materials in the waste stream and the environmental costs of squandering them through incineration or burial in a landfill. The inclusive, public redefinition process led to a new set of institutions for governing waste, from legislated waste reduction goals, to autonomy for programmatic experimentation, to-slowly over time-new roles for citizens and state. Instead of being locked in a service-provider-client relationship, Seattle's waste programs treat residents as partners in a project of resource stewardship, and cast the city government as both a responsible consumer and a programmatic innovator. Through this process, Seattle has achieved a remarkable recycling rate, but more importantly, has instituted curbside food scrap composting, nudged residents towards deeper engagement with their discards, and experimented successfully with restricting the use of toxic and hard-to-recycle materials. In Boston, on the other hand, from the moment of crisis through 2016, the city's waste managers retained traditional views of garbage and the project of waste management. Limited planning and limited input have served to maintain focus on conventional concerns about cleanliness, sanitation, and efficient disposal. As predicted by the waste regime, the city has a minimal recycling program that conforms to industry standards. I conceptualize the key differences between Seattle and Boston through a framework of wasteways. The term is borrowed from sewer engineering and redefined to provide a framework for understanding how unique municipal waste systems relate to dominant waste regimes. The transformation that took place in Seattle during the 1980s gave rise to an alternative wasteway--a system that is institutionally organized to resist the waste regime. Within Boston's mainstream wasteway, on the other hand, the city's waste system has operated, from the disposal crisis moving forward, as we would expect given the dominant regime. Analyzing municipal wasteways-a framework that can be applied to any city in any context, and could be expanded to include other urban systems-draws attention to the institutional changes that support infrastructural change. Recycling alone may not be sufficient to achieve sustainable materials practice, but the underlying institutional evolution in Seattle suggests that cities can achieve bold-even radical-changes to material practices at the urban scale. 4
by Lily Baum Pollans.
Ph. D. in Urban and Regional Planning

Les mangroves sont de plus en plus mentionnées comme outil de bioremédiation potentiel dans le traitement des eaux usées (EU). Actuellement, les effets des rejets d’EU sur la macrofaune, et plus particulièrement sur les crabes de mangrove, ne sont pas clairs. Ces espèces sont dites ingénieurs de cet écosystème, notamment grâce à leur activité de bioturbation qui permet, entre autres, l’infiltration des EU dans le sédiment via leurs terriers. L’objectif ont donc été d’étudier l’impact du rejet d’EU domestiques sur la physiologie (osmorégulation, métabolisme et balance oxydative) de 3 espèces de crabe (2 Sesarmidae et 1 Ocypodidae) par une approche combinant expérimentations en laboratoire et sur le terrain en utilisant un site pilote expérimental sur l’île de Mayotte. Ces crabes qui vivent dans la zone intertidale ont un mode de vie bimodal et font fréquemment face à des salinités variables. Ils sont de bons hyper-hypo-osmorégulateurs et sont adaptés à cette vie à l’interface entre terre et eau aussi bien au niveau de la régulation ionique que de la respiration. Les résultats indiquent que la densité des terriers diminue dans les zones d’écoulement des EU et que la communauté des espèces est modifiée avec la dominance de Parasesarma guttatum (PG) qui n’est pas une espèce bioturbatrice. Les EU induisent donc une modification potentielle du fonctionnement de l’écosystème. PG diminue son métabolisme alors que les deux autres espèces étudiées l’augmentent significativement. Immergées dans les EU, les trois espèces étudiées présentent des atteintes de la fonction osmorégulatrice (activité de la Na+/K+-ATPase et épaisseur d’épithélium branchiale) et de la balance oxydative (formation d’espèces réactives de l’oxygène dans l’hémolymphe et enzymes antioxydantes des branchies) en laboratoire mais des effets moins marqués sont observés chez les crabes maintenus in situ dans des terriers artificiels. Les biomarqueurs étudiés peuvent ainsi être utilisés pour mesurer l’état physiologique des crabes soumis à des rejets d’EU domestiques. Ces atteintes qui entraînent des coûts métaboliques supplémentaires peuvent mener à la réduction de leur fitness, contribuant à expliquer les observations écologiques. De plus, les résultats montrent que les crabes violonistes sont les plus sensibles, suivis des deux Sesarmidae alors que PG semble mieux adapté pour éviter les EU. Si aucun dysfonctionnement majeur n’a été observé à l’échelle de l’écosystème jusqu’à présent, il convient de maintenir un suivi régulier de ces espèces, en tenant compte de leur spécificité en termes d’activité bioturbatrice et de santé physiologique
Mangroves are increasingly proposed as a bioremediation tool for wastewater (WW) treatment. However, this practice can impact mangrove crabs which are key engineer species of the ecosystem through their bioturbation activities. Their burrows are directly involved in the bioremediation process allowing WW infiltration in the sediment. This study aimed to determine the effects of WW on the physiology (osmoregulation, bioenergetics, oxidative balance) of 3 species of crabs (2 Sesarmidae and 1 Ocypodidae) with laboratory and in situ experiments (burrow density and caging experiment in an experimental area with controlled WW releases on a mangrove located on the island of Mayotte). These crabs inhabit the intertidal area of variable salinity with a bimodal life (aquatic and terrestrial). They are good hyper-hypo-osmoregulators and well adapted to terrestrial life both in terms of osmotic and aerial breathing capacities. Burrow density decreases in flat areas where WW flows and crab community is altered with a marked dominance of Parasesarma guttatum (PG) (a species with no bioturbation activity). This change may induce drastic alterations of the ecosystem functioning. The bioenergetic response of PG is totally different from the other studied species. PG decreases its metabolic rate in WW but the other species have increased metabolic activity. Moreover, after laboratory exposure the 3 species show impairments in their osmoregulatory capacity (Na+/K+-ATPase activity and epithelium gill thickness) and oxidative balance (reactive oxygen species formation in haemolymph and antioxidant enzyme activity in gills) due to WW exposure in laboratory conditions. In situ, encaged crabs showed a similar but reduced pattern. These effects could decrease their fitness and may also explain the observed ecological changes. The biomarkers used in this study may be a useful tool to monitor crab populations. Moreover, our results show that fiddler crabs are the most sensitive to WW followed by other Sesarmidae. PG seems better adapted to avoid WW exposure. Even if no major dysfunction is observed at the ecosystem level yet, WW release should be carefully monitored nevertheless with an emphasis on crab bioturbation activity and their physiological health according to species sensitivity

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Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq
Cassava wastewater, wastewater from cassava (Manihot esculenta Crantz) processing industrial, is produced in volume large. When low-cost solutions are not viable, usually dumped in rivers or in the soil, provide environmental impact. The cassava wastewater fertilizer has potential because great its nutrients composition of especially potassium, but when used indiscriminately provokes of basic cations imbalance in soil. To evaluate the potential of cassava wastewater, two study were developed. The study first aimed to evaluate soil characteristics and leachate quality as function of cassava wastewater rates applied to columns containig soils of different textures. PVC columns (15 x 80 cm) were used to simulate a 60 cm soil profile. The soils studied were: Cohesive Yellow latosol, Carbonatic Haplic Vertisol and Orthic Quartzarenic Neosol. Aiming to supply the K requirement to maize, 4.7 m³ ha-1 of cassava wastewater was applied to the Vertisol and Latosol white the Neosolreceived 9.6 m3 -1ha. The Wastewater promoted increase on the K contents for the 0-20 cm layer of soil. The results showed that the cassava wastewater dose applied is safe regarding salinization and changes in floculation. In the second aimed to evaluate the potential of cassava wastewater as a potassium fertilizer to maize and the alteraions it provokes in soil chemical characteristic. Two soils (Carbonatic Haplic Vertisol and Orthic Quartzarenic Neosol) were put in 3 kg pots. These soils received wastewater doses equivalent to 0, 1, 2, 3, 4 and 5 times the amount of K recommended to maize. This was equivalent to 0, 4.7, 9.4, 14.1, 18.8, 23.6 m3-1 ha for the Vertisol and 0, 9.6, 19.2, 28.8, 38.5, 48.1 m3-1 ha the Neosol. The results showed that the application of cassava wastewater improved soil chemical characteristics, but it did not change soil pH. Cassava wastewater along with mineral mineral fertilizers poses potencial. On the other hand, wastewater alone was not able to provide the K requeriment to plant.
A água residuária da mandioca (manipueira), efluente oriundo da industrialização do processamento da mandioca (Manihot esculenta Crantz), é produzida em grande volume. Quando soluções de baixo custo não são viáveis, os efluentes são usualmente despejados em rios ou no solo, causando impacto ambiental. A manipueira apresenta grande potencial fertilizante devido à sua composição em nutrientes principalmente o potássio, mas quando utilizado de forma indiscriminada constitui implicação no desequilíbrio dos cátions básicos no solo. Com objetivo de avaliar o potencial do reaproveitamento da manipueira, foram desenvolvidos dois ensaios. No primeiro foram acondicionados, em colunas de PVC com 15 x 80 cm (diâmetro x altura), amostras de solos com diferentes texturas (Vertissolo Háplico Carbonático (VXk), Latossolo Amarelo Distrocoeso (LAdx) e Neossolo Quartizarênico Órtico (RQo)) coletadas até 60 cm. E com base no teor de potássio da manipueira, foram estabelecidas lâminas baseadas na recomendação potássica para milho, no VXk e LAdx foram aplicadas 4,7 m³ ha-1 e o RQo 9,6 m³ ha-1 ,este estudo objetivo-se avaliar os atributos do solo e da qualidade do lixiviado em resposta a aplicação da manipueira. A manipueira promoveu elevação nos teores de potássio trocável na camada de 0-20 cm. A dose aplicada não apresentou risco a salinização e alteração no grau de floculação. No segundo ensaio, objetivou-se avaliar o potencial da manipueira na adubação potássica na cultura do milho e alterações nos atributos químicos do solo. Foram acondicionados, em vasos com capacidade para 3 kg de solo, amostras de solos com diferentes texturas (Vertissolo Háplico Carbonático (VXk) e Neossolo Quartizarênico (RQo)) coletadas na profundidade de 0-20 cm, aplicou-se doses de manipueira correspondente a 0, 1, 2,3, 4 e 5 vezes a dose de adubação potássica recomendada para cultura do milho, que corresponderam a e 0, 9,6, 19,2, 28,8, 38,4, 48,1 m3-1 ha para o RQo e 0, 4,7, 9,4, 14,1, 18,8, 23,6 m3 ha -1 para o VXk, que foram complementadas com N, P e micronutrientes. Para cada solo foram acrescentados dois tratamentos adicionais: apenas adubação com manipueira na dose recomendada para K e adubação mineral (NPK). A manipueira aplicada após correção da acidez não promoveu efeito no pH do solo. O reaproveitamento da manipueira como fonte potássica apresentou potencial fertilizante quando complementada com adubação mineral.

The agricultural operations in India are suffering from a serious problem of shortage of electrical power on one side and economic and effective disposal of agriwaste stuff on the other. India being agriculture based country, 70% of its main income (share in GDP) comes from agriculture sector. Any enhancement of income from this sector is based upon adequate supply of basic inputs in this sector. Regular and adequate power supply is one such input. But, the position of power supply in our country defies both these characteristics. With a major portion of power produced being sent to the industrial and urban consumers, there is a perennial shortage of power in the agriculture sector. Consequently, there is an emergent need to produce more power in order to fulfil the needs of this sector effectively. One way of accomplishing this is setting up captive, preferably rural based, small power generation plants. In these power plants, instead of water-head, diesel oil or coal, we can use agri-residue to produce electricity. One such power plant (1–2 MW capacity) can satisfy the power need of 25 to 40 nearby villages. The agriwaste like rice straw, sugarcane-trash, coir-pith, peanut shells, wheat stalks & straw, cottonseed, stalks and husk, soyabean stalks, maize stalks & cobs, sorghum. Bagasse, wallnut shells, sunflower seeds, shells, hulls and kernels and coconut husk, wastewood and saw dust can be fruitfully utilized in power generation. This stuff is otherwise a waste and liability and consumes a lot of effort on its disposal; in addition to being a fire and health hazard. Agriwaste stuff which at present is available in abundance and prospects of its utilization in producing energy are enormous. This material can be procured at reasonably low rates from the farmers who will thus be benefited economically, apart from being relieved of the responsibility of its disposal. Agri-residue has traditionally been a major source of heat energy in rural areas in India. It is a valuable fuel even in the sub-urban areas. Inspite of rapid increase in the supply of, access lo and use of fossil fuels, agri-residue is likely to continue to play an important role, in the foreseeable future. Therefore, developing and promoting techno-economically-viable technologies to utilize agri-residue efficiently should be a persuit of high priority. Though there is no authentic data available with regard to the exact quantity of agricultural and agro-industrial residues, its rough estimate has been put at about 350 mt per annum. It is also estimated that the total cattle refuse generated is nearly 250 mt per year. Further, nearly 20% of the total land is under forest cover, which produces approximately 50 mt of fuel wood and with associated forest waste of about 5 mt.(1). Taking into account the utilization of even a portion (say 30%) of this agri-residue & agro-industrial waste as well as energy plantation on one million hectare (mha) of wastelands for power generation through bioenergy technologies, a potential of some 18000 MW of power has been estimated. From the foregoing, it is clear that there is an enormous untapped potential for energy generation from agri-residue. What is required is an immediate and urgent intensification of dedicated efforts in this field, with a view to bringing down the unit energy cost and improving efficiency and reliability of agri-waste production, conversion and utilisation, leading to subsequent saving of fossil fuels for other pressing applications. The new initiatives in national energy policy are most urgently needed to accelerate the social and economic development of the rural areas. It demands a substantial increase in production and consumption of energy for productive purposes. Such initiatives are vital for promoting the goals of sustainability. cleaner production and reduction of long-term risks of environmental pollution and consequent adverse climatic changes in future. A much needed significant social, economic and industrial development has yet to take place in large parts of rural India; be it North, West, East or South. It can be well appreciated that a conscious management of agri-residue, which is otherwise a serious liability of the farmer, through its economic conversion into electric power can offer a reasonably viable solution to our developmental needs. This vision will have to be converted into a reality within a decade or so through dedicated and planned R&D work in this area. There is a shimmering promise that the whole process of harvesting, collection, transport and economic processing and utilisation of agri-waste can be made technically and economically more viable in future. Thus, the foregoing paras amply highlight the value of agri-residue as a prospective source of electric power, particularly for supplementing the main grid during the lean supply periods or peak load hours and also for serving the remote areas in the form of stand-alone units giving a boost to decentralised power supply. This approach and option seems to be positive in view of its potential contribution to our economic and social development. No doubt, this initiative needs to be backed and perused rigorously for removing regional imbalances as well as strengthening National economy. This paper reviews the current situation with regards to generation of agriwaste and its prospects of economic conversion into electrical power, technologies presently available for this purpose, and the problems faced in such efforts. It emphasizes the need for an integrated approach to devise ways and means for generating electrical power from agriwaste; keeping in mind the requirements of cleaner production and environmental protection so that the initiative leads to a total solution.