Anaerobic waste stabilization ponds: a low-cost contribution to a sustainable wastewater reuse cycle.

Waste stabilization ponds (WSP) have been used extensively all over Europe over the last 50 yr for the treatment of municipal and industrial wastewaters. Models presented in manuals should be used only for guidance, and local experience from pilot and full-scale plants of a particular pond type is extremely valuable. Anaerobic WSP are single-stage, continuous- flow, anaerobic reactors operating at ambient temperatures and low volumetric organic loading as a pretreatment method. This article presents a literature review on the different available operational parameters of anaerobic ponds and examples from full-scale plant performance worldwide. On a wastewater management scheme, involving reuse for agriculture, the zero-energy demand of a waste stabilization pond series for the effective removal of organic and microbiological loading under existing legislation and guidelines will remain a valuable tool for sustainable development.