Household slow sand filters with and without water level control: continuous and intermittent flow efficiencies

Autor(es)

Maciel, Paulo Marcos Faria ^[1] ; Sabogal-Paz, Lyda Patricia ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Sao Carlos Sch Engn, Dept Hydraul & Sanitat, 400 Trabalhador Sao Carlense Ave, BR-13566590 Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ENVIRONMENTAL TECHNOLOGY; v. 41, n. 8, p. 944-958, APR 2 2020.
• Citações Web of Science: 7

Resumo

Four household slow sand filters were made out of PVC and operated in continuous and intermittent flows, with and without using a float to control the maximum level of water inside the units. The efficiency was evaluated as a function of Escherichia coli reduction and turbidity in water from the study prepared with kaolinite and E. coli suspension. The correlation of the efficiencies with the following operational parameters was evaluated: operating time, time after maintenance, filtration rate and head loss divided by bed thickness. The filters were classified as intermittent with float (IFF), intermittent without float (IF), continuous with float (CFF) and continuous without float (CF). IFF, CFF and CF had a non-woven blanket installed on top of the media. The results indicated that no significant statistical differences were found in E. coli reduction and turbidity between IFF and IF, however the former had filter runs over 80 days and the latter almost a quarter of this value. CFF matured faster and had less turbidity remaining in relation to CF. When comparing IFF with CFF, the former presented lower turbidity remaining (0.89 +/- 0.44 NTU versus 1.24 +/- 0.91NTU), but a lower reduction of E. coli (1.40 +/- 0.61 log versus 2.29 +/- 0.74 log). The time after maintenance was the most important operational parameter when evaluating the efficiencies. The float helped to mature the filter more quickly in a continuous flow and, together with a non-woven blanket, extended the filter runs in the intermittent flow. (AU)

• Processo FAPESP: 14/12712-8 - Biofiltros em areia operados em fluxo contínuo e em fluxo intermitente: desafios na construção, operação e manutenção
• Beneficiário: Lyda Patricia Sabogal Paz
• Modalidade de apoio: Auxílio à Pesquisa - Regular