Full text
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| Author(s): |
Simone May
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Escola Politécnica (EP/BC) |
| Defense date: | 2009-05-15 |
| Examining board members: |
Ivanildo Hespanhol;
Simar Vieira de Amorim;
Rodrigo Braga Moruzzi;
José Carlos Cunha Petrus;
Racine Tadeu Araújo Prado
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| Advisor: | Ivanildo Hespanhol |
| Abstract | |
The reuse of greywater and the rainwater catchment for non potable uses meets the premises of sustainability and the concept of water conservation. Properly conceived greywater reuse systems and rainwater catchment systems should follow four basic criteria: hygienic reliability, aesthetics, environmental protection and technical/economic feasibility. The greywater and the rainwater, when properly treated, can be used for consumption at buildings, for non potable purposes such as flushing toilet bowls, floors and backyards cleaning, garden irrigation, ornamental uses as in water mirrors and water fountains as long as its use avoid any risk to users health. Greywater can be divided in two groups: dark greywater and light greywater. The greywater is originated from bathtubs, showers, lavatories and washer machines. Dark greywater, has its origin from kitchen lavatory and dishwasher machine. Water from toilet bowls is not called greywater but wastewater. Greywater composition is mainly influenced by user habits and usually results on variations depending on the region, the culture, the costumes, the installation and the kind of chemical products used. Pathogenic microorganisms can be found on greywater and on rainwater as, for example, Escherichia Coli, commonly used as faecal contamination indicator. Greywater and rainwater treatment should be taken so that organic material can be removed or pathogenic microorganisms found can be inactivated, avoiding direct human contact and disease dissemination. Care on processing greywater reuse systems and rainwater catchment systems should be taken, as: verifying treated water quality, appropriated system maintenance, secure and efficient operation for the operator and for the system, the avoidance of crossing conections on distribution system, usage of alert signs about non potable water, different colors and different connection dimensions so that the reuse system offers secure operation for its users. This paperwork aims to the characterization and the treatment of greywater for non potable use in buildings, divided in two sections. The first section of the project aimed the residential greywater characterization through fisical, chemical and bacteriological analysis for quality evaluation. The second section was divided in two groups: the treatment of residential greywater and the treatment of collected rainwater. This project focus on the characterization and on the treatment of light greywater, defined as water collected from showers, lavatories and washer machines. Rainwater treatment was based on the results achieved from May (2004), annex #2. Filtration and chloride disinfection treatment was applied on rainwater and aerobic biological treatment was applied on greywater. Some of the parameters analysed during the monitoring period of the greywater treatment system, achieved a significant reduction as, for example: color: - 95.1%; turbidity: - 98.2%; TSS: - 94.1%; BOD: - 93.4%; COD: - 86.3%; TOC: - 84.9%; Thermotolerants Coliforms: - 99.8%; e Total Coliforms: - 97.8%. During the analysis, the residual chloride was kept on 0.8 to 1.7 mg/L range. On rainwater treatment system some parameters analysed during the monitoring period achieved the following reductions: color: - 62%; turbidity: - 75.7%; Thermotolerants Coliforms: - 100%; and Total Coliforms: - 100%. During the analysis, the residual chloride was kept on 0.6 to 1.2 mg/L range. Based on the results from the water analysis and on the results from the resulting treated water, its non potable uses should be stimulated. (AU) | |