Household slow sand filter efficiency with schmutzdecke evaluation by microsensors
| Autor: | Juliano José Corbi, Paulo Marcos Faria Maciel, Pilar Fernández-Ibáñez, Lyda Patricia Sabogal-Paz, P. S. M. Dunlop, Antonio Wagner Lamon, John Byrne, José Roberto Campos |
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| Rok vydání: | 2021 |
| Předmět: |
Continuous flow
0208 environmental biotechnology Significant difference 02 engineering and technology General Medicine 010501 environmental sciences Schmutzdecke Pulp and paper industry 01 natural sciences Slow sand filter 020801 environmental engineering Filter (aquarium) Total coliform Potable water ENGENHARIA HIDRÁULICA Environmental Chemistry Environmental science Turbidity Waste Management and Disposal 0105 earth and related environmental sciences Water Science and Technology |
| Zdroj: | Repositório Institucional da USP (Biblioteca Digital da Produção Intelectual) Universidade de São Paulo (USP) instacron:USP |
| Popis: | Slow sand filtration is a common technology providing potable water in rural households across Latin America, Asia and Africa. Two PVC household slow sand filters (HSSF) were operated in continuous (C-HSSF) and intermittent (I-HSSF) flow modes for eight consecutive months. A non-woven blanket was installed on the fine sand top to facilitate cleaning with scheduled maintenance undertaken every 30 days. The efficiency of each HSSF was evaluated via physico-chemical indicators (reduction of turbidity and colour) with biological performance assessed via total coliform and E. coli enumeration post treatment. There were no statistically significant differences between the continuous flow and intermittent flow models for physical-chemical and total coliform reduction parameters. However, when evaluating E. coli, C-HSSF performed better (p = 0.02). The non-woven blanket was subjected to weekly analysis using a Clark-type amperometric microsensor (diameter < 20 µm), which measured dissolved oxygen (DO) concentration in the adherent biofilm. DO microprofiles illustrated a variation in biofilm growth, which were associated with a progressive increase in the HSSF efficiency. The maximum DO depletion value measured during several months of operation showed no significant difference between I-HSSF and C-HSSF (p = 0.98). The microsensor measurements provided unprecedented results in real time. These results can help to understand the efficiency of the filter in relation to the biofilm growth, the dissolved oxygen depletion and turbidity removal. |
| Databáze: | OpenAIRE |
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