Comparison between sand filters media and non woven synthetic fabric in the effici...
Removal of heavy metals from water by slow filtration with nonwoven blankets wit...
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Author(s): |
Flavia Ferreira de Souza dos Santos
Total Authors: 1
|
Document type: | Doctoral Thesis |
Press: | Campinas, SP. |
Institution: | Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia Agrícola |
Defense date: | 2015-05-15 |
Examining board members: |
José Euclides Stipp Paterniani;
Gerson Araújo de Medeiros;
Marco Roberto Pires;
Cassiana Maria Reganhan Coneglian;
Denis Miguel Roston
|
Advisor: | Tulio Assunção Pires Ribeiro; José Euclides Stipp Paterniani |
Abstract | |
Non-woven synthetic fabric is an easily available and low-cost material which has brought satisfactory results in terms of both the quality of produced water and its operational value. The aim of this research is to assess the performance of a slow filter made up exclusively of non-woven synthetic fabrics of a number of different thicknesses and to compare it to that of a traditional sand filter. A pilot filtering system was built where the two slow filters operate in a parallel way under the influence of three filtering rates (3, 6 and 9 m3.m-2.d-1). Along the filtering runs the evolution of the headloss and the physical-chemical and bacteriological parameters of both raw water and water treated through the 12 thicknesses (ranging from 1 to 40 cm) of non-woven were monitored as well as that filtered through sand. The slow non-woven filter yielded long-term runs when compared to the sand filter, as well as reducing the frequency and complexity of the filter¿s cleaning process. The formation of schmutzdecke was observed on the superficial layer of non-woven filter, a process which had a similar maturing period to that of the sand filter, approximately 15 days. The satisfactory performance of the slow non-woven synthetic fabric filter covered all three filtering rates. In terms of the removal of apparent color and turbidity of raw water it met the drinkability standards set by the existing legislation. In terms of the removal of heterotrophic bacteria, total coliform and E. coli the non-woven filter obtained an efficiency level above 99,5%, statistically similar to the slow sand filter. The results indicate the optimal thickness of non-woven synthetic fabric for apparent colour and turbidity removal to be 25 cm, and suggest that a 15cm thickness would be enough to remove, with the possibility of using filtering rates considered elevated by slow filtering treatment standards (9 m3.m-2.d-1). Therefore, it concludes that the filter medium constituted exclusively of 25-cm-thick non-woven synthetic fabric has the potential to substitute sand in slow-filtering water treatment once it has obtained similar performance to the slow sand filter (AU) | |
FAPESP's process: | 11/09968-2 - Comparison between sand filters media and non woven synthetic fabric in the efficiency of slow filtration for water treatment |
Grantee: | Flavia Ferreira de Souza dos Santos |
Support Opportunities: | Scholarships in Brazil - Doctorate |