Pretreatment usingOpuntia cochenilliferafollowed by household slow sand filters: technological alternatives for supplying isolated communities

Autor(es)

Souza Freitas, Barbara Luiza ^[1] ; Sabogal-Paz, Lyda Patricia ^[1]

Afiliação do(s) autor(es)

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

• Tipo de documento: Artigo Científico
• Fonte: ENVIRONMENTAL TECHNOLOGY; v. 41, n. 21, p. 2783-2794, SEP 18 2020.
• Citações Web of Science: 9

Resumo

Household slow sand filter (HSSF) performance in continuous and intermittent flows was evaluated when influent water was treated with a natural coagulant extracted fromOpuntia cochenillifera. The water under study, used as influent, had a turbidity of 111 +/- 17.3 NTU. When clarifying the water withO. cochenillifera, the best condition obtained was 30 mg L(-1)in natural pH (without correction), generating clarified water with turbidity satisfactory to filters operation (7.83 +/- 2.32 NTU). The results indicated a better performance of continuous flow HSSF in turbidity removal (79.2% +/- 8.39%) and higher efficiency of intermittent flow HSSF in the removal ofE. coli(2.86 log +/- 0.79 log for 12 h pause period and 2.41 log +/- 0.42 log for 4 h pause period). For the sake of comparison, the evaluated HSSFs had the same production (60 L day(-1)). The impact on the interruption of the 96-h feed into the HSSFs was analysed and the results indicated a significant change in the quality of the filtered water after resuming the operation. This fragility of technology must be considered when it is implemented as lack of water can be a reality in the target communities. Acute toxicological assays withC. xanthuslarvae showed no toxicity for pretreated and filtered water; however, more testing should be performed. (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