Artigos de revistas: "On-site wastewater systems"

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Branz, S., J. Tolliver e M. Brandt. "Community On-site Wastewater Systems". Proceedings of the Water Environment Federation 2001, n.º 11 (1 de janeiro de 2001): 163–64. http://dx.doi.org/10.2175/193864701790860010.

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Scandura, J. E., e M. D. Sobsey. "Viral and bacterial contamination of groundwater from on-site sewage treatment systems". Water Science and Technology 35, n.º 11-12 (1 de junho de 1997): 141–46. http://dx.doi.org/10.2166/wst.1997.0724.

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On-site septic tank-soil absorption systems treating domestic wastewater have contaminated groundwaters with enteric viruses and other pathogens and caused drinking waterborne outbreaks. The factors influencing pathogen transport, survival and fate at on-site wastewater treatment systems remain inadequately characterised. We studied the survival and transport of a model enterovirus (BE-1) and faecal coliform bacteria in four on-site wastewater treatment systems (three conventional and one low pressure, small pipe diameter, pumped system) located in sandy soils typical of the coastal plains. Septic system wastewaters were seeded seasonally with known amounts of BE-1 and the fate of BE-1, faecal coliforms and other wastewater constituents were followed for three months in seeded wastewaters and groundwaters of drainfield monitoring wells. BE-1 levels in seeded wastewaters declined exponentially by kinetics consistent with a 3d hydraulic residence time. BE-1 was detected in ground waters of monitoring wells as early as 1d after seeding and persisted up to two months. Virus detection in ground water was greater in winter than in summer and was positively associated with proximity to septic effluent distribution lines, drainfield soils with the lowest clay content, elevated ground water pH and shallower vadose zones. Viruses were not strongly associated with either distance from septic tank or faecal coliform levels in groundwater. Under optimum conditions, virus reductions were as high as 9 log10, but in systems with the most coarse (sand) soils and highest water tables (most shallow vadose zones), there was extensive ground water contamination by viruses and other wastewater constituents. Under some conditions, septic systems in sandy coastal plains soils can contaminate ground water with viruses and other wastewater constituents.

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Hellström, Daniel, e Lena Jonsson. "Evaluation of small on‐site wastewater treatment systems". Management of Environmental Quality: An International Journal 17, n.º 6 (novembro de 2006): 728–39. http://dx.doi.org/10.1108/14777830610702548.

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Fastenau, Frits A., Jaap H. J. M. van der Graaf e Gerard Martijnse. "Comparison of Various Systems for On-Site Wastewater Treatment". Water Science and Technology 22, n.º 3-4 (1 de março de 1990): 41–48. http://dx.doi.org/10.2166/wst.1990.0181.

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Diffuse pollution, caused by direct discharges from individual houses, small built-up nuclei, farms, camp-sites, etc., for which connection to central wastewater treatment systems is unfeasible, may be significantly reduced by on-site treatment. Based on a large scale research, including intensive field-research work on 14 systems of different types and sizes in a range equal to population equivalents (p.e) of 5 - 200 persons, 8 different types of system were compared. The comparison involved technological features, such as removal efficiency, reliability, operational and maintenance aspects, environmental impacts and land claims, together with economical features showing significant differences. Advantages and disadvantages of each system are highlighted to enable a selection of suitable systems to be made. When no limiting factors are present, it was found that - in general-infiltration systems (infiltration pits; infiltration trenches) have the best features for on-site treatment up to 100 p.e. For larger capacities, or when infiltration is not possible, the rotating biological contactor will be the best solution mainly because of the lower costs.

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C. Roland Mote. "A Parallel Distribution Controller for On-Site Wastewater Systems". Applied Engineering in Agriculture 2, n.º 2 (1986): 120–22. http://dx.doi.org/10.13031/2013.26724.

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McCray, John E., e Sara H. Christopherson. "On-Site Wastewater Systems and Interactions with the Environment". Journal of Hydrologic Engineering 13, n.º 8 (agosto de 2008): 653–54. http://dx.doi.org/10.1061/(asce)1084-0699(2008)13:8(653).

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Yamagata, H., M. Ogoshi, Y. Suzuki, M. Ozaki e T. Asano. "On-site water recycling systems in Japan". Water Supply 3, n.º 3 (1 de junho de 2003): 149–54. http://dx.doi.org/10.2166/ws.2003.0020.

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Non-potable urban water reuse is Japan's main water reuse practice, which includes water for environmental uses, in-stream flow augmentation, toilet flushing, and industrial reuse. On-site water recycling systems reclaim wastewater on site as well as harvest rainwater in one or more large buildings and distributing the reclaimed water within the buildings for non-potable reuse. Based on our survey conducted in 1999 on current status of on-site water recycling systems in 23 wards of the Tokyo Metropolitan Government District, the following findings are reported in this paper: (1) on the average, 61% of non-potable water demand is met by reclaimed water, and the deficit is made up by tap water from city water supply, (2) biological treatment or ultrafiltration processes can provide reliable treatment and suitable water quality. Some technical problems such as odor from on-site treatment facilities have occurred in a few buildings, (3) there has been no serious accident involving human health by accidentally ingesting reclaimed water, and (4) there is a scale merit in the construction cost of on-site water recycling systems. An on-site wastewater recycling system larger than 100 m3/d is more economically justifiable when compared to a conventional domestic water supply system. An on-site water recycling system can provide an effective, safe, and economical urban water resource for non-potable water reuse applications.

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Whitehead, J. H., e A. Leventhal. "On-site wastewater management system design and landslide risk assessment". Water Science and Technology 51, n.º 10 (1 de maio de 2005): 55–63. http://dx.doi.org/10.2166/wst.2005.0351.

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On-site wastewater management system design and performance is significant in assessing landslide risk in areas with potential for slope instability. Much of the development in Pittwater, NSW, local government area is on steep coastal land which has a history of slope instability. Concern over cases of poorly performing or failing on-site wastewater systems and the recognition that these and newly designed systems could be contributory to slope instability has been a factor in Pittwater Council, NSW, requiring that landslide risk assessment be undertaken for new and amended on-site wastewater management systems in potentially unstable areas. This paper describes the wastewater management system design and landslide risk assessment undertaken at Pittwater Youth Hostel in accordance with the Australian Geomechanics Society's Geotechnical Risk Management procedure to comply with the Pittwater Policy. The work completed illustrates both necessary and effective interaction of the wastewater and geotechnical professions to achieve a successful outcome for the client. It is likely that this professional interaction will be increasingly common along the NSW coast and elsewhere.

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Ho, G., S. Dallas, M. Anda e K. Mathew. "On-site wastewater technologies in Australia". Water Science and Technology 44, n.º 6 (1 de setembro de 2001): 81–88. http://dx.doi.org/10.2166/wst.2001.0346.

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Domestic wastewater reuse is currently not permitted anywhere in Australia but is widely supported by the community, promoted by researchers, and improvised by up to 20% of householders. Its widespread implementation will make an enormous contribution to the sustainability of water resources. Integrated with other strategies in the outdoor living environment of settlements in arid lands, great benefit will be derived. This paper describes six options for wastewater reuse under research by the Remote Area Developments Group (RADG) at Murdoch University and case studies are given where productive use is being made for revegetation and food production strategies at household and community scales. Pollution control techniques, public health precautions and maintenance requirements are described. The special case of remote Aboriginal communities is explained where prototype systems have been installed by RADG to generate windbreaks and orchards. New Australian design standards and draft guidelines for domestic greywater reuse produced by the Western Australian State government agencies for mainstream communities are evaluated. It is recommended that dry composting toilets be coupled with domestic greywater reuse and the various types available in Australia are described. For situations where only the flushing toilet will suffice the unique “wet composting” system can be used and this also is described. A vision for household and community-scale on-site application is presented.

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Kuan, Wen-Hui, Ching-Yao Hu, Li-Wei Ke e Jung-Ming Wu. "A Review of On-Site Carwash Wastewater Treatment". Sustainability 14, n.º 10 (10 de maio de 2022): 5764. http://dx.doi.org/10.3390/su14105764.

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In recent years, people’s environmental awareness has increased. The high density of the urban population has caused a considerable increase in the demand for car washing services, which has created large quantities of car wash wastewater. The main pollutants in car wash wastewater are detergents, dirt, oil, and grease. Untreated wastewater released into rainwater sewer systems or other water bodies may pollute the water and generate excessive bubble foams, which negatively affects urban appearance. Car washes are divided into mechanical car washes and manual or self-service car washes. In general, car washes have a small operation and scale, occupy limited land, and cannot afford wastewater treatment costs. Therefore, most car washes are not equipped with wastewater treatment facilities. Consequently, the discharge of wastewater from car washes negatively affects the water quality in the surrounding environment and results in wasteful use of water resources. This study reviewed 68 research papers on the quality, treatment techniques, treatment costs, and treatment effectiveness of car wash wastewater to provide a reference for car wash operators to contribute to the preservation of water resources. We found that there is a higher chance of recycling car wash wastewater when combing two different techniques for car wash wastewater treatment.

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Randall, C. W. "Changing needs for appropriate excreta disposal and small wastewater treatment methodologies or The future technology of small wastewater treatment systems". Water Science and Technology 48, n.º 11-12 (1 de dezembro de 2004): 1–6. http://dx.doi.org/10.2166/wst.2004.0789.

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Recent developments will strongly influence the design and utilization of small wastewater treatment systems in the future, e.g. population increases in non-sewered rural areas and developing countries; increasing impairment of surface water quality; the construction of occupied high-rise buildings in metropolitan areas; the development of planned but somewhat isolated communities, growing shortages of water that mandate reuse of wastewaters. It is well known that there is a very strong linkage between wastewater disposal methods in rural areas and developing countries and the general health of the population. These problems could be greatly reduced or prevented by the utilization of well known excreta disposal and small wastewater treatment system technologies, but the development of more innovative on-site systems is needed. It is expected that future environmental and public health pressures in developed countries will require increasingly stringent effluent limitations for small and on-site wastewater disposal systems, based primarily on nutrient discharges. Both on-site and small-scale technologies are available for the more stringent requirements, but innovative and more economical designs are needed for wide-spread acceptance. Water reuse should be a consideration for the designs of these systems. Implementation and utilization of well known technologies are needed, but the obstacles are often more social and political than economical.

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Pundsack, Jonathan, Richard Axler, Randall Hicks, Jerald Henneck, Delwin Nordman e Barbara McCarthy. "Seasonal Pathogen Removal by Alternative On-Site Wastewater Treatment Systems". Water Environment Research 73, n.º 2 (março de 2001): 204–12. http://dx.doi.org/10.2175/106143001x139182.

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Herrmann, Inga, Brenda Vidal e Annelie Hedström. "Discharge of indicator bacteria from on-site wastewater treatment systems". DESALINATION AND WATER TREATMENT 91 (2017): 365–73. http://dx.doi.org/10.5004/dwt.2017.21416.

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Weiss, Philipp, David Eveborn, Erik Kärrman e Jon Petter Gustafsson. "Environmental systems analysis of four on-site wastewater treatment options". Resources, Conservation and Recycling 52, n.º 10 (agosto de 2008): 1153–61. http://dx.doi.org/10.1016/j.resconrec.2008.06.004.

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Ritter, W. F., e R. P. Eastburn. "A review of denitrification in on-site wastewater treatment systems". Environmental Pollution 51, n.º 1 (1988): 49–61. http://dx.doi.org/10.1016/0269-7491(88)90238-2.

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Abdullah, H., A. Abusam, A. Mydlarczyk, A. Al-Dhafeeri, F. Al-Ajeel, A. Ali, M. Al-Jomaa e R. Al-Yaseen. "Performance Evaluation of Commercial Package Systems Used in Kuwait for on-Site Treatment and Reuse of Domestic Wastewater". International Journal of Environmental Science and Development 14, n.º 1 (2023): 22–29. http://dx.doi.org/10.18178/ijesd.2023.14.1.1410.

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Kuwait’s wastewater management scheme consists of a huge centralized sewerage system that transports all wastewater generated for treatment at central municipal plants for wastewater treatment. However, there are a few remote sites that are still not connected to the public sewerage system. In such sites, on-site systems such as conventional septic tank or package systems are commonly used. This study assessed the performance of two package systems used in Kuwait for on-site wastewater treatment and reuse. Wastewater samples were collected weekly for five months from influent and effluent streams of two package systems located at Ahmedi and Kadhmah areas of Kuwait. Comparison of the means of the laboratory results to the guidelines of Kuwait Public Authority for Environment (KEPA) indicated that the effluents of the two systems are suitable to be reused as irrigation water. However, results obtained also showed that performances of both units were highly fluctuating.

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Huntsman, Brent E., Charles A. Staples, Carter G. Naylor e Jim-Bob Williams. "Treatability of Nonylphenol Ethoxylate Surfactants in On-Site Wastewater Disposal Systems". Water Environment Research 78, n.º 12 (novembro de 2006): 2397–404. http://dx.doi.org/10.2175/106143005x72966.

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Williamson, Eric. "Cold Climate Performance Analysis of On-Site Domestic Wastewater Treatment Systems". Water Environment Research 82, n.º 6 (junho de 2010): 512–18. http://dx.doi.org/10.2175/106143009x12529484815557.

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Kohler, Laura E., JoAnn Silverstein e Balaji Rajagopalan. "Resilience of On-Site Wastewater Treatment Systems after Extreme Storm Event". Journal of Sustainable Water in the Built Environment 6, n.º 2 (maio de 2020): 04020008. http://dx.doi.org/10.1061/jswbay.0000909.

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Dey, Ayanangshu, e Dennis D. Truax. "Evaluation of On-site Wastewater Disposal Systems in Mississippi Coastal Areas". Water, Air, & Soil Pollution 223, n.º 5 (9 de novembro de 2011): 2145–56. http://dx.doi.org/10.1007/s11270-011-1011-6.

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Finch, S. D., D. E. Radcliffe e L. T. West. "Modeling Trench Sidewall and Bottom Flow in On-Site Wastewater Systems". Journal of Hydrologic Engineering 13, n.º 8 (agosto de 2008): 693–701. http://dx.doi.org/10.1061/(asce)1084-0699(2008)13:8(693).

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Joy, Douglas, Claude Weil, Anna Crolla e Shelly Bonte-Gelok. "New technologies for on-site domestic and agricultural wastewater treatment". Canadian Journal of Civil Engineering 28, S1 (1 de janeiro de 2001): 115–23. http://dx.doi.org/10.1139/l00-100.

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Recently publicized problems of water quality in rural parts of Canada are again bringing increasing attention to methods of dealing with wastewater in rural environments. This includes wastewater from both domestic (principally single-family homes) and agricultural sources. Previous practices which relied on dispersal with little treatment are increasingly unacceptable not only because of the recognition of the weakness of this approach but also because of the increasing intensification of land use in rural areas. Thus the need for additional and improved technologies for treating wastewater, on site, has increased. Because of this, new technologies have been developed which provide better treatment than previous approaches that also rely on natural processes. Examples of the former include peat, sand, and foam filters for domestic on-site wastewater systems. Engineered wetlands to treat barnyard runoff or rural municipal lagoon effluent is an example of a technology using natural processes. This paper describes some of these new technologies and their potential advantages.Key words: rural, wastewater, septic, manure, farm, on site, technologies.

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Humphrey, C. P., M. A. O'Driscoll e M. A. Zarate. "Controls on groundwater nitrogen contributions from on-site wastewater systems in coastal North Carolina". Water Science and Technology 62, n.º 6 (1 de setembro de 2010): 1448–55. http://dx.doi.org/10.2166/wst.2010.417.

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The goal of this study was to evaluate the influence of soil type and separation distance to water table on dissolved inorganic nitrogen concentrations in groundwater adjacent to on-site wastewater systems. Groundwater nitrogen species (NO3−-N and NH4+-N) and groundwater levels adjacent to 16 on-site systems in three different soil groups (group I- sand, group II- coarse loams and group III -sandy clay loams) were monitored for 15 months (January 2007–March 2008) in coastal North Carolina. On-site systems in soil group I had the highest concentrations of dissolved inorganic nitrogen (median of 18.9 mg/L) in groundwater, and most frequently (mean 61%) exceeded 10 mg/L, followed by systems in soil group II (11.0 mg/L, 50%) and soil group III (2.6 mg/L, 9%), respectively. Groundwater NH4+-N concentrations near on-site systems in soil groups I and II that maintained a 60 + cm separation to the seasonal high water table were 4 mg/L lower in relation to systems that had <60 cm separation, but median NO3−-N concentrations were 6.5 mg/L higher. On-site systems in group I and II soils are prone to groundwater nitrogen loading with separation distance often controlling the nitrogen speciation in groundwater near on-site systems.

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Gunady, Maria, Natalia Shishkina, Henry Tan e Clemencia Rodriguez. "A Review of On-Site Wastewater Treatment Systems in Western Australia from 1997 to 2011". Journal of Environmental and Public Health 2015 (2015): 1–12. http://dx.doi.org/10.1155/2015/716957.

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On-site wastewater treatment systems (OWTS) are widely used in Western Australia (WA) to treat and dispose of household wastewater in areas where centralized sewerage systems are unavailable. Septic tanks, aerobic treatment units (ATUs), and composting toilets with greywater systems are among the most well established and commonly used OWTS. However, there are concerns that some OWTS installed in WA are either performing below expected standards or failing. Poorly performing OWTS are often attributed to inadequate installation, inadequate maintenance, poor public awareness, insufficient local authority resources, ongoing wastewater management issues, or inadequate adoption of standards, procedures, and guidelines. This paper is to review the installations and failures of OWTS in WA. Recommendations to the Department of Health Western Australia (DOHWA) and Local Government (LG) in regard to management strategies and institutional arrangements of OWTS are also highlighted.

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Fastenau, Frits A., Jaap H. J. M. van der Graaf e Gerard Martijnse. "Bottlenecks in the Implementation of On-Site Wastewater Treatment Plants on a Large Scale in The Netherlands". Water Science and Technology 22, n.º 3-4 (1 de março de 1990): 291–98. http://dx.doi.org/10.2166/wst.1990.0214.

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More than 95 % of the total housing stock in the Netherlands is connected to central sewerage systems and in most cases the wastewater is treated biologically. As connection to central sewerage systems has reached its economic limits, interest in on-site treatment of the domestic wastewater of the remaining premises is increasing. A large scale research programme into on-site wastewater treatment up to population equivalents of 200 persons has therefore been initiated by the Dutch Ministry of Housing, Physical Planning and Environment. Intensive field-research work did establish that the technological features of most on-site biological treatment systems were satisfactory. A large scale implementation of these systems is however obstructed in different extents by problems of an organisational, financial and/or juridical nature and management difficulties. At present research is carried out to identify these bottlenecks and to analyse possible solutions. Some preliminary results are given which involve the following ‘bottlenecks':-legislation: absence of co-ordination and absence of a definition of ‘surface water';-absence of subsidies;-ownership: divisions in task-setting of Municipalities and Waterboards; divisions involved with cost-sharing;-inspection; operational control and maintenance; organisation of management;-discharge permits;-pollution levy;-sludge disposal. Final decisions and practical elaboration of policies towards on-site treatment will have to be formulated in a broad discussion with all the authorities and interest groups involved.

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Jenssen, P. D., e R. L. Siegrist. "Technology Assessment of Wastewater Treatment by Soil Infiltration Systems". Water Science and Technology 22, n.º 3-4 (1 de março de 1990): 83–92. http://dx.doi.org/10.2166/wst.1990.0187.

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Infiltration of wastewater in buried soil infiltration systems has been promoted as a low cost, effective alternative for treatment and disposal of wastewater flows from commercial developments and small communities. Unlike many mechanical wastewater treatment systems, soil infiltration systems are subject to complex, far-reaching influences related to natural site conditions and the interaction of wastewater with a dynamic soil and ground water system. As a result, design and performance relationships are not always well defined and systems are often implemented based on local tradition and empiricism. Consequently there is a need for improvement of design criteria especially for large subsurface wastewater treatment systems. Successful performance starts with thorough site investigations, where large scale infiltration tests or tracer studies might be needed. The hydraulic loading rate is a principal design parameter. An integrated approach for assessment of the hydraulic loading rate based on soil type and wastewater quality is suggested. In general, trench design should be preferred over beds, but rational criteria for selection of optimal geometry is lacking. Purification performance of subsurface wastewater infiltration systems is generally good. Estimates of purification on the basis of soil grain size, soil depth and loading rate can be given.

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Thoma, K., P. A. Baker e E. B. Allender. "Design Methods for the Development of Wastewater Land Disposal Systems". Water Science and Technology 27, n.º 1 (1 de janeiro de 1993): 77–86. http://dx.doi.org/10.2166/wst.1993.0020.

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Recent changes in legislation governing water quality management of receiving water bodies have led to a reappraisal of wastewater land disposal techniques. However, more stringent regulations have also necessitated the development of a multi-disciplinary planning approach, to ensure that land based wastewater disposal is functionally and environmentally sustainable in the long-term. Of principal concern are the long term impact of nutrients, salt and other potential contaminants on the soils of the receiving site and on downstream water quality. Assessment of hydrological, soil physical and geological characteristics, together with civil construction and service considerations, assist in the determination of receiving-site selection, application area and balance storage volume, irrigation method, environmental monitoring system specification etc. Analysis and interpretation of wastewater and soil chemical characteristics determines the pre-application water treatment required, and aliows long-term monitoring of the effect of wastewater disposal on the receiving-site soils. Two case-studies are presented. One describes the planning and design of a recently commissioned land-disposal system using industrial wastewater from a chemical process plant to irrigate a Eucalypt plantation in western metropolitan Melbourne. The other reports on the on-going assessment and planning of a large-scale land-disposal system proposed to accommodate the treated sewage effluent from a large north-west Victorian regional city.

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Patel, T., N. O'Luanaigh e L. W. Gill. "The efficiency of gravity distribution devices for on-site wastewater treatment systems". Water Science and Technology 58, n.º 2 (1 de agosto de 2008): 459–65. http://dx.doi.org/10.2166/wst.2008.364.

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A detailed analysis of different types of gravity distribution devices, designed to split on-site wastewater effluent equally between percolation trenches, has been carried out both in the laboratory and also in the field under realistic loading conditions. Five different types of distribution device have been compared: a V-notch distribution box, stilling chamber box, T-splitters with and without baffles and tipping bucket device. The trials carried out in the laboratory with clean water showed that flow distribution for all devices was sensitive to both the off-level installation angles and variable flow rates, with the most stable performance achieved using the T-splitters with baffles and tipping bucket devices. In parallel to this, the on-site flow regime experienced at two sites was continuously monitored using a tipping bucket and data-logger over eighteen month periods, finding that the most common flow rates at the distribution unit were in the range of 0.1–2.5 L/min. The on-site performance of these devices receiving both septic tank and secondary treated effluent showed that significant solid deposition and biofilm development had severely affected the equal distribution between the trenches, hence highlighting the need for regular maintenance to ensure efficient performance over time after installation.

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Kohler, Laura E., JoAnn Silverstein e Balaji Rajagopalan. "Modeling on-site wastewater treatment system performance fragility to hydroclimate stressors". Water Science and Technology 74, n.º 12 (7 de outubro de 2016): 2917–26. http://dx.doi.org/10.2166/wst.2016.467.

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Increasing variability of climate-related factors, especially precipitation and temperature, poses special risks to on-site wastewater treatment systems (OWTS), which depend on subsurface saturation conditions for treatment and dispersion of wastewater. We assess OWTS fragility – the degree to which a system loses functionality – as a step to characterizing the resilience of residential wastewater treatment systems. We used the frequency and indexed severity of OWTS failures and resulting repairs to quantify fragility as a function of hydroclimate variables, including precipitation, temperature and stream flow. The frequency of each category of repair (minor, moderate and major) for 225 OWTS obtained from Boulder County public health records was modeled as a function of climate factors using a generalized linear model with a Poisson distribution link function. The results show that prolonged precipitation patterns, with monthly rainfall >10.16 cm, influence OWTS fragility, and complete loss of OWTS functionality, requiring replacement, is impacted by high temperatures, frequency of wetter-than-normal months, and the magnitude of peak stream flow in the watershed. Weather-related covariates explained 70% of the variability in OWTS major repair data between 1979 and 2006. These results indicate that fragility arising from climate factors, and associated costs to owners, environmental and health impacts, should be considered in planning, design and operation of OWTS.

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HU, SHUNFU, e JIANPENG ZHOU. "DEVELOPING A GIS-BASED INFORMATION MANAGEMENT SYSTEM FOR ON-SITE WASTEWATER TREATMENT FACILITIES". International Journal of Software Engineering and Knowledge Engineering 18, n.º 04 (junho de 2008): 503–13. http://dx.doi.org/10.1142/s0218194008003738.

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On-site wastewater treatment facilities (WWTFs) collect, treat, and dispose wastewater from dwellings that are not connected to municipal wastewater collection and treatment systems. They serve about 25% of the total population in the United States from an estimated 26 million homes, businesses, and recreational facilities nationwide. There is currently no adequate coordinated information management system for on-site WWTFs. Given the increasing concern about environmental contamination and its effect on public health, it is necessary to provide a more adequate management tool for on-site WWTFs information. This paper presents the development of an integrated, GIS-based, on-site wastewater information management system, which includes three components: (1) a mobile GIS for field data collection; (2) a World Wide Web (WWW) interface for electronic submission of individual WWTF information to a centralized GIS database in a state department of public health or state environmental protection agency; and (3) a GIS for the display and management of on-site WWTFs information, along with other spatial information such as land use, soil types, streams, and topography. It is anticipated that this GIS-based on-site wastewater information management system will provide environmental protection agencies and public health organizations with a spatial framework for managing on-site WWTFs and assessing the risks related to surface discharges.

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Olivier, L., V. Dubois, Y. LeGat e C. Boutin. "Statistical analysis of the effluent quality of 231 on-site sanitation facilities in France monitored during a 6-year period". Water Science and Technology 80, n.º 2 (15 de julho de 2019): 203–12. http://dx.doi.org/10.2166/wst.2019.252.

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Abstract On-site wastewater treatment systems are approved by the French regulation based on the results of platform tests following the European standard NF EN 12566-3. In addition to this approval for the treatment system, at least 90% of outlet concentrations have to be below 30 mg L−1 for total suspended solids (TSS) and 35 mg L−1 for biochemical oxygen demand. The aim of this study is to evaluate the effluent quality of these treatment systems on site, i.e. under real operating conditions, and to assess their performances. Between 2011 and 2016, 1,286 treated wastewater samples were taken from 231 on-site sanitation facilities in France. Data collected are heterogeneous and a robust statistical methodology (using a generalized log-linear model) was used to study the effects of four explanatory variables (treatment systems, loading rate, aging and sampling methods) on the distribution of treated wastewater concentrations. The model calculates median outlet concentrations depending on the effects identified. Its application allowed studying and comparing the outlet median concentrations of 21 on-site sanitation systems classified into nine categories and three groups. Four treatment systems out of the 21 monitored showed TSS median outlet concentrations below 10 mg L−1 and four treatment systems have TSS medians higher than the regulatory threshold of 30 mg L−1.

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Watanabe, T., K. Kuniyasu e H. Ohmori. "Anaerobic and Aerobic Submerged Bio-Filter System for Small Scale On-Site Domestic Sewage Treatment". Water Science and Technology 27, n.º 1 (1 de janeiro de 1993): 51–57. http://dx.doi.org/10.2166/wst.1993.0014.

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In order to prevent water pollution and satisfy the demands for flush toilets in regions where a public sewerage system has not been in service, some on-site small scale domestic wastewater treatment processes called GAPPEI JOHKASOU have been developed to treat black water and gray water together in an individual house. Prior to its technical development, the characteristics of wastewater discharged from individual houses should be measured. The possibility of application of anaerobic filter is examined for processing organic wastewater at low concentration like in domestic wastewater, and an anaerobic filteris successfully developed to lengthen the sludge removal interval, since the flow rate of wastewater from individual houses is characterized by a large variation. It is difficult to serve the centralized treatment systems in many regions. Thus, a small GAPPEI JOHKASOU has been developed and propagated for by individual houses in such regions.

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Boguniewicz-Zablocka, Joanna, Iwona Klosok-Bazan, Andrea G. Capodaglio e Joanna Ploskonka. "Planning the optimal solution for wastewater management in rural areas - case study". MATEC Web of Conferences 174 (2018): 01035. http://dx.doi.org/10.1051/matecconf/201817401035.

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Water management and associated wastewater management is an inseparable element of life and development of modern societies. Collection and treatment of wastewater has a significant impact on the environment and economy, both at the local and global level. It is therefore necessary to proceed to activities that ensure proper wastewater management, especially in rural and low-density areas, where it is necessary to search for optimal solutions with regard to sewage systems, including wastewater treatment plants. One of the solution for wastewater treatment from houses without access to sewerage collection system is the construction of on-site wastewater treatment plants. Construction of on-site wastewater treatment plant poses a number of challenges for municipalities and potential investors and has been discussed by many. Aim of this paper is to draw the current status and perspectives of on-site wastewater treatment systems in Poland, with focus on selected case study from rural areas. The paper presents a way to solve the problem of wastewater management in the municipality of Pietrowice Wielkie using local biological wastewater treatment plants. The article presents technological, technical and economical aspects of the above-mentioned solutions and analysis of the advantages and disadvantages of the system proposed by the municipality.

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Mattila, H., E. Santala e J. Aho. "Consumer managed co-operative - a solution for progressing wastewater management in rural areas". Water Science and Technology 48, n.º 11-12 (1 de dezembro de 2004): 385–91. http://dx.doi.org/10.2166/wst.2004.0886.

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In Finland the question of appropriate wastewater treatment in rural areas has become very prominent during the last years. The new Environmental Protection Act stipulates that wastewaters must be treated to the extent that they cannot have a negative impact on nature. The Ministry of the Environment is currently preparing a decree specifying the requirements. The draft of the decree proposes that on-site treatment units should decrease the BOD load by 90, total phosphorus load by 85 and total nitrogen load by 40 per cent. To meet the new requirements, the old systems that include septic tanks only need more efficient wastewater treatment methods. Whatever technical solution is selected, the house owner must pay for it. At the moment, even the septic tanks are emptied and maintained irregularly. More sophisticated wastewater treatment methods definitely need more maintenance, which cannot be made the sole duty of the house owners. One potential organisational alternative for managing wastewater treatment in rural areas is the co-operative. Finland has one such pioneering co-operative formed for on-site sanitation. Varsinais-Suomi Water Services Co-operative provides the house owner with professional assistance in wastewater treatment at a reasonable cost. Suvisaari Water Services Co-operative is another new organisation selling sewerage services to its members. But its technology is different: this co-operative operates an LPS-sewerage system instead of on-site treatment.

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Gibbons, Andrew, Kristofor R. Brye, Sam Dunn, Edward E. Gbur, Andrew N. Sharpley e Wen Zhang. "Increased Effluent Dosage Effects on On-Site Wastewater Treatment Systems of Differing Architecture Type". Journal of Environmental Protection 06, n.º 06 (2015): 651–70. http://dx.doi.org/10.4236/jep.2015.66059.

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Penn, Roni, Manfred Schütze, Jens Alex e Eran Friedler. "Impacts of onsite greywater reuse on wastewater systems". Water Science and Technology 75, n.º 8 (6 de fevereiro de 2017): 1862–72. http://dx.doi.org/10.2166/wst.2017.057.

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Together with significant water savings that onsite greywater reuse (GWR) may provide, it may also affect the performance of urban sewer systems and wastewater treatment plants (WWTPs). In order to examine these effects, an integrated stochastic simulation system for GWR in urban areas was developed. The model includes stochastic generators of domestic wastewater streams and gross solids (GSs), a sewer network model which includes hydrodynamic simulation and a GS transport module, and a dynamic process model of the WWTP. The developed model was applied to a case study site in Israel. For the validation of the sewer simulator, field experiments in a real sewer segment were conducted. The paper presents the integration and implementation of these modules and depicts the results of the effects of various GWR scenarios on GS movement in sewers and on the performance of the WWTP.

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Willers, H. C., X. N. Karamanlis e D. D. Schulte. "Potential of closed water systems on dairy farms". Water Science and Technology 39, n.º 5 (1 de março de 1999): 113–19. http://dx.doi.org/10.2166/wst.1999.0229.

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A more sustainable water management on dairy farms is necessary because of rising tap water production costs and exhaustion of groundwater resources in an increasing number of areas. Alternative water sources like rain water collected from roofs and yards and effluents from on-site wastewater treatment should be considered. The objective of this paper is to discuss options for closed water systems on dairy farms. Animal drinking and cleaning of milking equipment are major water demands on dairy farms. In some regions large volumes are needed for grassland irrigation or manure flushing. Treatment of dairy farm wastewater in constructed wetland systems seems to produce good quality effluents. The most plausible options for closed water systems on dairy farms are the collection and use of rain water and treatment and reuse of wastewater for irrigation, manure flushing and animal drinking water. Whether effluents are safe to be used as animal drinking water should be subject to further research.

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Gill, Laurence, Bruce Misstear, Paul Johnston, Niall O’Luanaigh, H. Barthelemy e S. W. Dean. "Natural Attenuation of Endocrine Disrupting Chemicals in On-Site Domestic Wastewater Treatment Systems". Journal of ASTM International 6, n.º 3 (2009): 102170. http://dx.doi.org/10.1520/jai102170.

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Sélas, B., A. Lakel, Y. Andres e P. Le Cloirec. "Wastewater reuse in on-site wastewater treatment: bacteria and virus movement in unsaturated flow through sand filter". Water Science and Technology 47, n.º 1 (1 de janeiro de 2003): 59–64. http://dx.doi.org/10.2166/wst.2003.0016.

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In on-site wastewater treatment plants, effluents are pre-treated by septic tank and treated by soil infiltration or sand filtration systems, with unsaturated flow conditions. These systems remove efficiently carbon, nitrogen and suspended solids. But for microbial pollution, the treatment efficiency depends on the hydrodynamic behaviour and filtering media characteristics. Contamination of superficial water and groundwater due to pathogenic viruses and pathogenic bacteria is responsible for many diseases. The objective of this study is to approach the mechanisms and operating conditions to control bacteria and virus release in the environment. Experiments were carried out on reactors of different length packed with sand. Hydraulic load of 90 cm.d−1 with a pulse periodic flow was used. The influence of chemical composition of the solution on the treatment efficiency has also been studied. For the first time, the residence time distribution (RTD) has been studied using a conservative tracer (KI), to determine the main hydrodynamic parameters. For the second time, the RTD with bacterial and viral tracers (E. coli, bacteriophage MS2) was applied, with the aim to define microbial behaviour in filtering media, including adsorption and filtration phenomena. This work allowed us to determine retardation factors according to the hydraulic loads and chemical composition.

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Johannessen, Erik, Arild Schanke Eikum e Tore Krogstad. "Evaluation of sampling methods for monitoring effluent phosphorus for on-site wastewater treatment systems". Water Science and Technology 65, n.º 11 (1 de junho de 2012): 2049–54. http://dx.doi.org/10.2166/wst.2012.107.

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More than 1,600 prefabricated on-site wastewater treatment plants are in operation in the Morsa watershed in Norway. As of 2010 a monitoring program on the performance of these plants is in effect. Sampling methods for wastewater treatment plants is discussed, and different methods are compared. The study includes six different plant models, of which all are prefabricated package plants. The parameters investigated were total phosphorus (Tot-P), orthophosphate (PO4-P) and suspended solids (SS). Diurnal curves showed no apparent repetitive variation over 24 h intervals, indicating good equalization and robust design to compensate for highly variable loadings. A comparison of grab samples and time proportional composite samples showed almost identical average values, and a paired two-tailed Student's t-test indicates no statistically significant difference between the sampling methods. The results indicate that equivalent results should be expected irrespective of sampling method, and, as composite sampling is attributed to much higher costs, it is recommended that grab sampling should be used when a large number of plants are evaluated.

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Levett, K. J., J. L. Vanderzalm, D. W. Page e P. J. Dillon. "Factors affecting the performance and risks to human health of on-site wastewater treatment systems". Water Science and Technology 62, n.º 7 (1 de outubro de 2010): 1499–509. http://dx.doi.org/10.2166/wst.2010.434.

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Aerobic wastewater treatment systems (aerobic systems) are the preferred choice in a region overlying a karstic aquifer used for drinking water supplies, as they are thought to provide better protection to groundwater and human health than standard septic systems. However, aerobic systems in operation do not always perform to design standard; while this is often blamed on lack of maintenance, few studies have investigated the link directly. This study investigates the performance of domestic on-site wastewater treatment systems in South Australia, and compares effluent quality to maintenance records. Effluent from 29 septic tanks and 31 aerobic systems was analysed for nutrients, physico-chemical parameters and microbiological indicators. Aerobic systems generally provided greater treatment than septic tanks, yet most aerobic systems did not meet regulatory guidelines with high levels of indicator bacteria in 71% of samples. The effect of system size, number of household occupants and maintenance on aerobic system treatment performance was analysed: chlorine levels were positively correlated with time of last service, and nutrient concentrations were positively correlated with the number of occupants. A microbial risk assessment revealed the observed irrigation practices to be high risk; and sufficient residence time in the aquifer cannot be guaranteed for protection of groundwater used for drinking. Additional preventive measures such as irrigation management or post treatment of drinking water supply (such as UV disinfection) are required to meet public health targets.

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Pundsack, J. W., R. E. Hicks e R. P. Axler. "Effect of alternative on-site wastewater treatment on the viability and culturability of Salmonella choleraesuis". Journal of Water and Health 3, n.º 1 (1 de março de 2005): 1–14. http://dx.doi.org/10.2166/wh.2005.0001.

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The objective of this study was to determine how alternative on-site wastewater treatment systems (i.e. subsurface flow constructed wetlands, intermittent sand filters and intermittent peat filters) affect the viability and culturability of Salmonella choleraesuis (serotype typhimurium, ATCC 23567). Influent was a high strength septic tank effluent (BOD5 240–344 mg L−1, TN ∼100 mg L−1, TP ∼ 15 mg L−1) at the Natural Resources Research Institute's (NRRI) alternative treatment system test facility in northern Minnesota. Treatment systems were inoculated with cultures of S. choleraesuis for 5–7 consecutive days in summer and winter during 1998–99. After the seeding, outflow samples were taken until Salmonella counts were sustained at background levels. In addition to culture-based enumeration, S. choleraesuis abundances were also measured using fluorescent in situ hybridization (FISH) alone and in combination with the direct viable count method (DVC) to determine if plate counts underestimated total and viable Salmonella abundances and if the Salmonella cell viability changed after passing through the treatment systems. In most cases, total and viable cell abundances in treatment system effluents were several orders of magnitude higher than cultured cell abundances. Our results indicate that the culture-based method underestimated viable concentrations of the model pathogen, S. choleraesuis. Salmonella cell viability decreased in effluents during the summer but increased during the winter. Using a culture-based enumeration method alone to determine removal efficiencies of bacterial indicators and pathogens for wastewater treatment systems may result in artificially high estimates of effective treatment.

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Liljestrand, H. M., e S. M. Parten. "Design of On-Site Treatment Systems in Caliche Soils". Water Science and Technology 28, n.º 10 (1 de novembro de 1993): 83–87. http://dx.doi.org/10.2166/wst.1993.0210.

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Caliche soils, weathered limestone soils of high calcium carbonate content and and low organic content, are common in regions with limestone sedimentary geology and arid to semi-arid climate. Currently, there are no standards other than hydraulic soil properties for the design and construction of on-site wastewater treatment systems in caliche soils. Experimental studies were performed to investigate biological transformation rates for organic carbon to inorganic carbon and organic nitrogen to nitrate, using four different caliche soils and the range of recommended hydraulic loading rates. The experimental results indicate that oxygen demanding materials readily decay over short distances in caliche soils. Efficiency of removal for TOC was >97%. However in three of the four caliche soils, nitrate concentrations were significantly higher than the background and the control cases. The high calcium carbonate content of the caliche soils leads to solutions well buffered with respect to pH and alkalinity. Nitrification rates are very rapid in these soils which are buffered at the optimum pH range for Nitrosomonas growth. The low organic carbon content of caliche soils results in low denitrification rates. Nitrate in the effluent is the limiting pollutant in the determination of appropriate loading rates, drain field area, and land requirements. Phosphate and metal aqueous concentrations are acceptably low and are limited by solubility control in the open system equilibrium model.

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Talbot, Pierre, Ginette Bélanger, Martin Pelletier, Gilles Laliberté e Yves Arcand. "Development of a biofilter using an organic medium for on-site wastewater treatment". Water Science and Technology 34, n.º 3-4 (1 de agosto de 1996): 435–41. http://dx.doi.org/10.2166/wst.1996.0461.

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In recent years, many authors identified peat-based systems as a very promising technology for on-site wastewater treatment. In that context, Premier Tech has been working, since 1988, on the development and commercialization of a peat-based biofilter suitable for on-site wastewater treatment. This research and development programme comprised three major phases: an experimental phase where one type of peat out of 21 was chosen to be used in biofilters; a second phase where two prototype biofilters were installed in the field and their performances followed for 5 years; and a third phase where 4 biofilters were installed in order to demonstrate the adaptability of the system. The results obtained in this three-phase programme allowed the introduction on the market of a compact, reliable, and easy to operate biofilter requiring little investment from the home owner. In this paper an overview of the research and development programme carried out in the last 8 years in relation to on-site wastewater treatment is given.

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Kärrman, E., Å. Erlandsson, D. Hellström, B. Björlenius e P. Tidåker. "Centralised or decentralised sanitation in Swedish summerhouse areas in transition to permanent living?" Water Science and Technology 56, n.º 5 (1 de setembro de 2007): 157–64. http://dx.doi.org/10.2166/wst.2007.568.

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The standard of wastewater management is high in Sweden. Around 90% of the population is connected to central wastewater treatment plants with high requirements of nutrients removal; however, still the problem with algae blooms in the Baltic Sea exists. The aim of the VeVa project was to develop a simple and user-friendly Excel-based model to support environmental decisions of how to select wastewater systems for housing areas where no central sewer system exists. The VeVa model deals with two types of environmental issues: substance flow analysis and energy analysis. Six system structures were studied for the transition area Lillängsdal in Värmdö municipality sorted in three categories: 1) on-site systems for single households; 2) local collective systems; 3) connection to central systems. All studied system structures, except for a Sand filter system, fulfilled the goals of reducing phosphorus and BOD7 according to Swedish guidelines for on-site systems in sensitive areas. All studied systems, except for the Sand filter system, have the potential to fulfil the Swedish National Environmental goal to recycle 60% phosphorus to productive land. The systems with central wastewater treatment plant and local wastewater treatment are the most energy efficient alternatives that also fulfil the requirements of discharges and environmental goals regarding phosphorus recycling.

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Kazora, Amos Shyaka, e Khaldoon A. Mourad. "Assessing the Sustainability of Decentralized Wastewater Treatment Systems in Rwanda". Sustainability 10, n.º 12 (5 de dezembro de 2018): 4617. http://dx.doi.org/10.3390/su10124617.

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Kigali city, the capital of Rwanda, relies on decentralized, on-site, wastewater systems due to the absence of central sewerage systems and the limited finances to construct sustainable sanitation infrastructures. However, the city has increasingly shown failures in managing these on-site systems either at individual or collective levels. This study aims at assessing the sustainability of the operated collective public semicentralized sewage systems in Kigali city. To fully cover the sustainability assessment of such collective systems, the methods used were field observation, questionnaires, interviews, and laboratory tests. The study also reviewed the influence of national ruling sanitation legal instruments in addressing development, operation and management of such decentralized wastewater systems. The results showed that the sustainability levels of these systems were low in the technical, socioeconomic status, institutional, and legal dimensions. While the sustainability level was fair for the environmental quality. In conclusion, the research highlighted that the improved sanitation coverage does not mean coverage in terms of sewerage connection proportions for wastewater collection as these connections do not imply safe and sustainable treatment before being discharged into the environment.

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Gray, S., e N. Booker. "Wastewater services for small communities". Water Science and Technology 47, n.º 7-8 (1 de abril de 2003): 65–71. http://dx.doi.org/10.2166/wst.2003.0672.

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Connection to centralised regional sewage systems has been too expensive for small-dispersed communities, and these townships have traditionally been serviced by on-site septic tank systems. The conventional on-site system in Australia has consisted of an anaerobic holding tank followed by adsorption trenches. This technique relies heavily on the uptake of nutrients by plants for effective removal of nitrogen and phosphorus from the effluent, and is very seasonal in its efficiency. Hence, as these small communities have grown in size, the environmental effects of the septic tank discharges have become a problem. In locations throughout Australia, such as rural Victoria and along the Hawkesbury-Nepean River, septic tanks are being replaced with the transport of sewage to regional treatment plants. For some isolated communities, this can mean spending $20,000-$40,000/household, as opposed to more common connection prices of $7,000/household. This paper explores some alternative options that might be suitable for these small communities, and attempts to identify solutions that provide acceptable environmental outcomes at lower cost. The types of alternative systems that are assessed in the paper include local treatment systems, separate blackwater and greywater collection and treatment systems both with and without non-potable water recycling, a small township scale treatment plant compared to either existing septic tank systems or pumping to a remote regional treatment facility.The work demonstrated the benefits of a scenario analysis approach for the assessment of a range of alternative systems. It demonstrated that some of the alternatives systems can achieve better than 90% reductions in the discharge of nutrients to the environment at significantly lower cost than removing the wastewater to a remote regional treatment plant. These concepts allow wastewater to be retained within a community allowing for local reuse of treated effluent.

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Tsuzuki, Yoshiaki, Thammarat Koottatep, Thitiphon Sinsupan, Supattra Jiawkok, Chira Wongburana, Suraphong Wattanachira e Yuttachai Sarathai. "A concept for planning and management of on-site and centralised municipal wastewater treatment systems, a case study in Bangkok, Thailand. I: Pollutant discharge indicators and pollutant removal efficiency functions". Water Science and Technology 67, n.º 9 (1 de maio de 2013): 1923–33. http://dx.doi.org/10.2166/wst.2013.053.

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The concept of pollution load indicators for planning and management of the mixture conditions of centralised and on-site wastewater treatment systems has not been discussed in detail so far. In this paper, pollutant discharge (load) indicators and pollutant removal efficiencies were quantitatively analysed to develop a part of a strategy for planning and management of municipal wastewater treatment systems (WWTSs) under the mixture conditions in Bangkok, Thailand, as a case study. Pollutant discharge indicators of on-site WWTSs were estimated based on the relevant literature. Three kinds of pollutant removal efficiency function at centralised wastewater treatment plants (CWWTPs) were empirically developed for biological oxygen demand, chemical oxygen demand, total nitrogen, total phosphorus, total coliforms and faecal coliforms based on the existing CWWTP management data. These results will be integrated into the scenario-based analysis in the second paper in the series. The results will be base datasets, and the concept and estimation methods can be applied for wastewater treatment planning and management in other areas.

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Gao, Qiuju, Kristin M. Blum, Pablo Gago-Ferrero, Karin Wiberg, Lutz Ahrens e Patrik L. Andersson. "Impact of on-site wastewater infiltration systems on organic contaminants in groundwater and recipient waters". Science of The Total Environment 651 (fevereiro de 2019): 1670–79. http://dx.doi.org/10.1016/j.scitotenv.2018.10.016.

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Dev, Aakash, Timo C. Dilly, Amin E. Bakhshipour, Ulrich Dittmer e S. Murty Bhallamudi. "Optimal Implementation of Wastewater Reuse in Existing Sewerage Systems to Improve Resilience and Sustainability in Water Supply Systems". Water 13, n.º 15 (21 de julho de 2021): 2004. http://dx.doi.org/10.3390/w13152004.

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A transition from conventional centralized to hybrid decentralized systems has been increasingly advised recently due to their capability to enhance the resilience and sustainability of urban water supply systems. Reusing treated wastewater for non-potable purposes is a promising opportunity toward the aforementioned resolutions. In this study, we present two optimization models for integrating reusing systems into existing sewerage systems to bridge the supply–demand gap in an existing water supply system. In Model-1, the supply–demand gap is bridged by introducing on-site graywater treatment and reuse, and in Model-2, the gap is bridged by decentralized wastewater treatment and reuse. The applicability of the proposed models is evaluated using two test cases: one a proof-of-concept hypothetical network and the other a near realistic network based on the sewerage network in Chennai, India. The results show that the proposed models outperform the existing approaches by achieving more than a 20% reduction in the cost of procuring water and more than a 36% reduction in the demand for freshwater through the implementation of local on-site graywater reuse for both test cases. These numbers are about 12% and 34% respectively for the implementation of decentralized wastewater treatment and reuse.

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