Environmental risk assessment for dissolved oxygen and free ammonia in a river

Dissolved oxygen and un-ionized ammonia are two relevant water quality parameters in a surface water body. Dissolved oxygen low levels and free ammonia high concentration produce negative consequences on the aquatic ecosystem. The paper proposes the use of a deterministic water quality model coupled with a risk assessment method based on first and second order moments to predict the efficiency of a strategy of river restoration. This approach appears to be useful and consistent with the purpose to obtain valuable prediction about negative effects of pollutants discharge on aquatic life.