This paper aims to develop a model for calculating the hydraulic and water quality parameters of wastewater within sewers. Information from the wastewater collection network and the transmission line in Birjand were used to verify the model performance. The parameters used for modelling quality changes include the yield constant for biomass (Y_H), the maximum specific growth rate (μ_H), the saturation constant for dissolved oxygen (K_OG) and the saturation constant for readily biodegradable substrate within a biofilm (K_SF), as well as the Gauckler–Manning–Strickler coefficient (n). They were selected from references and were verified at the calibration stage comparing measurements with the modelling values. Inputs of the created model are the average concentrations of dissolved oxygen and chemical oxygen demand of the incoming wastewater, the flow rate of wastewater at the exit point of the network, physical characteristics of the pipes and the height of drops within the sewer network. The amount of dissolved oxygen at different positions of the sewer network was calculated. The acceptable calculated sum of squares of errors and the correlation coefficient (R²) of the calibrated model for dissolved oxygen were 1.6872 and 0.77, respectively.

本文旨在开发一种模型，用于计算下水道内废水的水力和水质参数。来自 Birjand 废水收集网络和输电线路的信息用于验证模型性能。用于模拟质量变化的参数包括生物量的产量常数 ( Y _H )、最大比生长速率 ( μ _H )、溶解氧的饱和常数 ( K _OG ) 和生物膜内易于生物降解的底物的饱和常数 ( K _SF )，以及 Gauckler-Manning-Strickler 系数 ( n）。它们是从参考文献中挑选出来的，并在校准阶段将测量值与建模值进行比较来验证。所创建模型的输入是流入废水的溶解氧和化学需氧量的平均浓度、管网出口处的废水流量、管道的物理特性和下水道管网内的水滴高度。计算了污水管网不同位置的溶解氧量。溶解氧校准模型的可接受计算误差平方和和相关系数（R ^{2 ）分别为1.6872和0.77。}