Verification of two design approaches for stabilization ponds

• Published in: Water research (Oxford) 1993, Vol.27 (9), p.1447-1454
• Main Authors: Ellis, K.V., Rodrigues, P.C.C.
• Format: Article
• Language: English
• Subjects: Applied sciences; Biochemical oxygen demand; BOD 5 removal; Effluent treatment; Exact sciences and technology; faecal coliforms; Filtration; first-order complete-mix approach; Mathematical models; McGarry and Pescod; organic loading; Pollution; Q1; Sewerage works: sewers, sewage treatment plants, outfalls; stabilization ponds; temperature; Water treatment and pollution
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/0043-1354(93)90024-C

The stabilization pond system in Grand Cayman consists of two facultative ponds in parallel followed by two maturation ponds in series, operating over a limited mean annual temperature variation of 4.5°C and with a mean total retention time of 21.2 days. The results of the operation of these ponds over a 12-month period were analysed to verify the value of the first-order, complete-mix approach to design. Some appreciable support for the use of this approach was elucidated for the design of faculative ponds, particularly for the removal of faecal coliforms. First-order reaction coefficients of 0.357 d −1 at 30°C for BOD 5 removal (filtered effluent samples) and of 15.7 d −1 for faecal coliform removal were established for facultative ponds. Some attention was also given to various design approaches relating areal loading to temperature but with the limited temperature range available few conclusions could be drawn.