Disasters and emergency situations can disrupt the provision of clean water and hygienic sanitation, which are crucial for maintaining public health. Excreta disposal in emergencies has often been a low priority and this has led to the provision of unsuitable on-site sanitation systems in urban areas. A decision algorithm for the selection of adequate excreta-disposal solutions suitable for different disaster-relief scenarios is presented. The special requirements of a wastewater treatment system for deployment during an emergency are discussed and a semi-centralised system is recommended to serve 5000 refugees under a range of assumed loading conditions. Twenty-three aerobic, anaerobic and natural systems are considered for secondary treatment and a process-selection matrix is presented based around 16 evaluation criteria. A system layout is developed based around several sanitation facilities including sedimentation tanks connected to a centralised roughing trickling filter and an activated sludge unit, which provides optimal performance against the evaluation criteria. The system provides the required treatment performance in an easy-to-deploy, low-cost compact installation. © 2007 CIWEM.

Process selection Wastewater treatment disaster relief

emergency urban area refugee priority journal disaster algorithm Algorithms disaster relief sanitation wastewater Disasters waste treatment Article waste water management Process selection waste disposal Settling tanks filter Excreta disposal Wastewater treatment Activated sludge process activated sludge sedimentation tank decision making public health