ABSTRACT
This study presents a methodology to determine the appropriate location for effluent disposal in a low-flow river using numerical modelling, via a case study of a river located in Southern Brazil, considering disposal of landfill leachate with known characteristics. There are four key steps: 1) a principal component analysis (PCA) for a set of representative parameters; 2) a decision flowchart for proper water quality models; 3) a modified Water Quality Index (WQI) using the resulting concentrations and 4) simulation on 1D and 2D models and WQI calculation and evaluation. The PCA highlights eight relevant parameters: ammonia (NH3), chloride (Cl−), biochemical oxygen demand (BOD), total phosp horus, nitrite (NO2−), nitrate (NO3−), dissolved oxygen (DO) and total dissolved solids. Two models were considered suitable: HEC-RAS (1D) and SisBaHiA (2DH). After simulating the parameters in both models, a WQI was calculated for each location. Both HEC-RAS and SisBaHiA lead to the same effluent outfall location, showing that spatial discretisation does not affect the results.
Disclosure statement
No potential conflict of interest was reported by the author(s).