WATER QUALITY MODELING AND DISSOLVED OXYGEN BALANCE IN
STREAMS: A POINT SOURCE STREETER-PHELPS APPLICATION IN HARSIT
CASE
S. Serkan NAS1 and Evin NAS1
1
Department of Civil Engineering, Gümüshane Faculty of Engineering, Gümüshane
University, 29000 Gümüshane-Turkey
Subject index words: Critical dissolved oxygen deficit concentration; Dissolved oxygen
sag; River pollution; Streeter-Phelps equation; Watershed models.
Short Title: The Dissolved Oxygen Balance (Sag Curve) in Streams.
Total number of Tables: 2
Total number of Figures: 4
Contact Details:
Dr. S. Serkan NAS (corresponding author)
Complete Postal Address: Department of Civil Engineering, Gümüshane Faculty of
Engineering, Gümüshane University, 29000 Gümüshane-TURKEY
E-mail: serkannas@gmail.com or ssnas@ktu.edu.tr
Fax: + 90 (456) 233–7427
Telephone number: + 90 (456) 233 7425
Water Quality Modeling and Dissolved Oxygen Balance in Streams: A Point Source
Streeter-Phelps Application in Harsit Case
S. Serkan NAS1 and Evin NAS1
1
Department of Civil Engineering, Gümüshane Faculty of Engineering, Gümüshane
University, 29000 Gümüshane-Turkey
Abstract
The Harsit Stream flowing into the Black Sea is an important watershed in the northeastern
part of Turkey. The monthly averages of dissolved oxygen, carbonaceous biochemical
oxygen demand, temperature, pH, total suspended solids, total phosphorus and total
nitrogen were obtained for the water samples taken from Tekke, Akcakale and Haciemin
sites of the Harsit Stream. Water quality parameters were analyzed and evaluated
according to the WHO standards and Turkish Water Pollution Control Regulation.
At first, variations of dissolved oxygen profile were determined from dissolved
oxygen, temperature and carbonaceous biochemical oxygen demand measurements by
using point source Streeter-Phelps equation. Critical dissolved oxygen deficit values were
calculated for the monthly average from January 2005 to December 2005, which are below
the limit value (4 mgL-1) excluding April (7. 26 mgL-1) and May (5.98 mgL-1) in the Harsit
Stream having second class water quality in terms of dissolved oxygen concentration,
temperature, pH and biochemical oxygen demand. It is also seen that minimum dissolved
oxygen limit value (8 mgL-1), which is desired in the drinking waters, is under the limit
value in all months in case of a mixture. Particularly during summer months, the
consumption speed of oxygen is greater than the production speed of oxygen with
increasing temperature and decreasing discharge, and negative values (anoxia) on
dissolved oxygen sag are seen. These situations call for significant precautions and
treatment.
Key words: Critical dissolved oxygen deficit; Dissolved oxygen sag; River pollution;
Streeter-Phelps equation; Watershed models.