Revista Brasileira de Ciências Ambientais (Jul 2017)

INFILTRATION STUDIES ON SOAKAWAYS RECEIVING EFFLUENTS FROM SINGLE HOUSEHOLD UASB AND SEPTIC TANK REACTORS

  • José Lima de Oliveira Junior,
  • José Tavares de Sousa,
  • Andressa Muniz Santos,
  • Saionara Alexandre da Silva

DOI
https://doi.org/10.5327/Z2176-947820170413
Journal volume & issue
no. 43
pp. 131 – 139

Abstract

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Clogging tendency has been analyzed in sandy soil soakaways at pilot scale receiving either septic tank effluent (SUM1) or UASB effluent (SUM2) and also at laboratory scale (SUMB1 and SUMB2), in relation to Chemical Oxygen Demand (COD) and accumulated Suspended Solids (SS) concentrations. Clogging was also estimated, by modeling the predicted time for infiltration hydraulic failure. The laboratory results obtained with SUMB1 and SUMB2 confirmed the results obtained for SUM1 and SUM2, showing that soakaways built in sandy soils which receive effluent from septic tanks treating predominantly domestic wastewater tended to clog 58% faster than those receiving UASB effluent. The good correlation observed between the decrease in average infiltration rate and the time of operation suggests that the UASB reactor is a promising technological alternative to septic tanks as a pre‑treatment prior to effluent soil disposal for on‑site decentralized wastewater treatment systems.