Waste Stabilisation Ponds VI

Waste stabilisation pond systems are recognised worldwide as a low-cost and effective technology for efficient wastewater treatment. Over recent years they have undergone a renaissance in several countries to cope with new challenges: growing population, enhanced treatment requirements, footprint reduction, limitation of environmental impact, sludge management. This has lead to new technological and scientific developments. The increasing diversity of the technology offers the possibility of combining different types of ponds (anaerobic, facultative, maturation, deep, shallow, aerated, high rate algal ponds - and wetlands). There is a new interest in devices such as baffles, recirculation systems and gravel filters. The growing complexity of pond technology and the demand for greater performance predictability require more in depth knowledge of the mechanisms involved, most of which are greatly influenced by meteorological factors. Some of the key features of ponds - their high treatment efficiency, low energy consumption, low operation and maintenance costs - are shared by constructed wetland systems and there is growing interest in the possibilities offered by combinations of ponds and wetlands. To enable sharing of information and insights IWA's 6th Waste Stabilisation Ponds and 9th Wetland Systems (selected proceedings published as issue 9 of volume 51 of Water Science and Technology) conferences were organised at the same venue and joint sessions were held. Over 100 papers and posters on ponds were presented and following peer review 45 have been selected for these proceedings. They provide an overview of the latest technological developments and the most significant advances in our understanding of the physical and biological mechanisms involved in the removal of nutrients and micro-organisms; they will prove invaluable to anyone interested in the theory or application of waste stabilisation ponds.