TITLE:
Risk Modelling of Organic Pollution in Lake Sediments
AUTHORS:
Irina Schneider, Yana Topalova
KEYWORDS:
Biodegradable Organics, Enzyme Activity, Hydroelectric Power Plant, Iskar River, Self-Purification
JOURNAL NAME:
Journal of Environmental Protection,
Vol.7 No.5,
March
31,
2016
ABSTRACT: A risk situation of organic pollutants accumulation
in the sediments of the dams from Cascade “Middle Iskar” (NW Bulgaria) is
simulated in the present study. The aim is risk modelling of organic pollution
in lake sediments and on base of the investigated key chemical and
enzymological parameters to risk assessment. A model process in lab scale with addition of whey as a source of organic pollutants was simulated.
Two situations near to real conditions were studied: 1) at a decreased
concentration of organic pollutants (chemical oxygen demand was 0.265 gO2.kg-1)
in the case of discharge of sediments downstream of the river (control
situation); 2) at an accumulation of organic pollutants (chemical oxygen demand
was 1.463 gO2.kg-1) in the
sediments (risk event). The dynamics of chemical oxygen demand (COD),
concentration of proteins and lactose as well as of the key enzymological
indicators (phosphatase activity index—PAI, anaerobic dehydrogenase activity,
protease and ?-galactosidase activities) were investigated. The data from Risk
Assessment showed that there is a hazard from higher protein concentration at
the end of the process in comparison with the control situation. The risk about
COD and lactose concentration during the risk modelling was acceptable. The
obtained results showed that the PAI can be used as an indicator for early
warning of the organic pollution with protein nature.