| Abstrakt: |
The Dez River, as the third largest river in the country, plays an essential role in the economic, social and environmental life of North Khuzestan. Also, it is very important because it supplies water to more than 125 thousand hectares from the Dez plain and the lands downstream of this plain to the place of Bituminous Dam and provides a significant part of the environmental needs of the Karun River. The purpose of this research is to investigate the trend of quality and pollution along the Dez River and evaluate the effects of urban, agricultural and industrial wastewater discharges on the trend of pollution and quality of the Dez River in 131 intervals based on the QUAL2Kw model. In the calibration and validation stages of the model, it was determined that wide parameters such as flow geometry, river hydraulic conditions, water flow rate, aeration coefficients, pollutant entry points, nitrification rate, oxygen demand, etc. in the river are involved in qualitative modeling results. The results showed that QUAL2Kw water quality model is highly accurate in simulating quality parameters and pollution in Dez River. The trend of changes in quality parameters and pollution in the Dez River showed that this river is better in terms of BOD pollution due to the discharge of urban and industrial sewage, in terms of EC pollution due to the discharge of agricultural land drains (mainly sugarcane plan) and in terms of N-NH4 pollution It is in a critical condition due to urban and industrial sewage and drainage of agricultural lands. Therefore, it is suggested that all the wastewater of Dezful city, fish farming effluent, Haft Tepe complex and Pars paper factory should be treated and then discharged, but regarding agricultural drains, corrective measures such as improvement in the type of irrigation systems, fertilizers, the cultivation pattern of the area, etc., should be done at the source. [ABSTRACT FROM AUTHOR] |
