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Decentralised wastewater treatment
Wednesday, 04 November 2009 14:49
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Decentralized treatment systems


The management of decentralized systems of sewages in individual residences, or small teams, in isolated municipal or commercial installations and small settlements (under 10.000 p.e.), can be specified as the collection, treatment, disposal and/or re-use of flows locally. It is marked that in our country, bigger units of treatment of sewages (in urban centres with over 10.000 p.e.) have been manufactured and are functioned or find themselves in advanced stage.


The last years have been developed new technologies and more specifically small systems of treatment, that produce flows the same or better quality compared to big, conventional units of treatment. Such technologies can be applied mainly in rural regions. Examples of such technologies that include alternative technologies of collection and sewerage of wastewater, are various types of septic reservoirs with effluent filters, biorotors, nterminent sand filters, constructed wetlands, the systems of treatment that are based on the soil and on deeper geological shapings, lakes of stabilization and systems of aquaculture.
The application of decentralized systems of treatment of sewages, in combination with the re-use of their flows in various uses as the irrigation and growth of green or fire safety, has particularly expanded the last years in a lot of advanced countries and in the USA. It is appreciated that more from 60 millions persons today in the United States live in houses that are served by decentralized systems of collection and treatment of waste.ater. In the early '70s, with the voting of “Law on clean water”, it was announced that, it was only subject of time, before installations of sewages to be available almost in the all residents of USA. However, after 35 roughly years, it is today recognized that the cover of country with central cloacal networks it is not possible to be achieved, mainly for economic reasons (Crites and Tchobanoglous, 1998). With data that complete systems of sewerages and treatment of sewages with conventional processes, it will not be possible to materialized in the near future and that the increasing demand of available watery resources will be continued. It is explicit that the decentralized management of sewages is necessary for the growth of long-term strategies of management of environment and particularly the watery resources. Such systems constitute the improved technologies of septic reservoirs, the various types of filters, biorotors and natural systems (NWTS).


At the planning of small and decentralized wastewater treatment systems it needs accent in the following:

  • Simple operation without complex mechanic parts, low initial cost, very low cost operation of also maintainance.
  • Flexible and effective when are even presented interruptions of electric current, shock hydraulic charges, chemical/toxic substances
  • With minimal requirements of human potential for the operation maintainance
  • Most plants nowdays do not operate properly or the conditions of operation require enormous pecuniary sums
  • Each work of independent capacity should function effectively for a lot of years so that it protects the environment and is developed completely the money that they been spent for his manufacture.
Last Updated ( Thursday, 10 December 2009 12:46 )