Meeting stringent environmental and reuse requirements with an integrated pond system for the twenty-first century

Abstract

It is a long sought desire to modernize stabilization pond systems by increasing their efficiency to control malodors, to save land requirements and to improve their effluent quality, particularly for reuse purposes, while still capitalizing on natural energy saving processes such as anaerobiosis and photosynthesis. A full-scale demonstration modern integrated pond system was constructed in the town of Arad (22,000 inhabitants) located in the Negev desert of Israel. The integrated pond system is composed of the following units: (1) anaerobic covered ponds of which one is of the `submerged tent' novel design, including biogas collection and utilization for heating the bottom sludge; (2) two facultative ponds with internal recirculation; (3) a two stage rock filter to biologically remove excess algal biomass from the effluent; (4) three storage reservoirs operating in a sequential array of `fill, stay, draw', and (5) a seasonal reservoir. The final effluent is aimed at irrigation of various agricultural crops.