An Approach for Analysis of Natural Hazard Impacts on Activated Sludge Wastewater Treatment

The activated sludge process is a advansed biological wastewater treatment process for treating sewage or industrial wastewaters by using different aerobic types of microorganisms (biomass). In recent years, the activated sludge processes are shown to be significantly negative affected by the natural hazards (the climate factors) as extreme temperatures, intensive rainfall, etc. An approach for analysis of natural hazard (climate change) impacts on wastewater treatment process with activated sludge is proposed. The approach is based on qualitative analysis of the input-output static characteristics of the activated sludge process, involving uncertainties in the inflow parameters of the aerobic bioreactor. The process model is described by the system from two nonlinear ordinary equations with interval coefficients. The impact levels of one natural hazard on the activated sludge process are defined as a deviation between the nominal and the affected input-output characteristics. The negative effects are described by variation in given intervals of some process coefficients and are calculated as percentages (deviations) from the nominal process coefficients. This analysis of natural hazard impacts on activated sludge wastewater treatment process is necessary in order to operate such system stable and efficiently.