Advanced waste stabilization ponds (oxidation ponds, anaerobic, maturation, HRSP - high rate stabilization ponds, algae ponds, lagoons, rock filters), plug-flow, hydraulics, tracers, stratification, Juanicó, fixed biomass, sewage and wastewater treatment, sanitation, low energy, aeration, recirculation.

HOME

New concepts for the design of advanced waste stabilization ponds
(lagoons)

Numerous different types of ponds have been developed during the years:

Anaerobic ponds (open or covered)
Aerobic ponds (maturation or polishing)
Facultative ponds
Ponds with or without recirculation
High rate stabilization ponds (HRSP)
Partially mixed and bi-dimensional plug-flow ponds
Ponds for both municipal and industrial effluents
etc.

Numerous contributions to the understanding of waste stabilization ponds have been communicated since the creation of the IWA (International Water Association) WSP Specialist Group in 1987 (Dr. Juanicó is a founder member of the Group).
WSP design practice today is much different from what used to be 20 years ago.
We have now a new generation of waste stabilization ponds that are smaller, more efficient, more reliable, with less or no odor problems, and which release effluents of better quality than the “old” generation.

Hydraulic short-circuiting between inlet and outlet and hydraulically dead areas are the most common reason for failure of waste stabilization ponds and the greatest challenge for designers. There is a strong disagreement between the theoretical hydraulic models and the actual hydraulic pattern of effluents within the pond. Thus, kinetics of waste stabilization ponds is still poorly known, because the processes in real scale ponds are generally masked by the unknown actual hydraulic pattern.

Main new concepts and tools available for the design of modern waste stabilization ponds are:

Hydraulics:
- actual hydraulic pattern (tracer studies) and development of tools to improve it
- pond shape (sometimes optimal shapes may very "rare" but drastically improve the performance of the ponds)
- wind effect on wastewater circulation within the pond
- stratification control
- a non-steady-state approach to reactor analysis (see paper by Juanicó and Friedler)
- use of both horizontal and vertical baffles to force plug-flow conditions (see paper by Juanicó)
- sequential batch operation

Kinetics:
- pond acceleration by low-energy mixing, aeration or re-circulation
- pond acceleration by addition of fixed biomass
- combination of ponds with more intensive treatment units

Out-of-the-pond elements:
- different types of pond covers and devices to avoid smell release
- intensive anaerobic pre-treatment to reduce pond size
- post-treatment for algae removal (rock filters, constructed wetlands) and other requirements

Design of the sewage treatment series:
- ponds of different sizes instead of modularization
- use of wastewater storage reservoirs for irrigation, controlled discharge and other purposes