Inhibition kinetics of salt-affected wetland for municipal wastewater treatment

A mathematical model was developed in order to describe the system behavior and performance of a constructed wetland (CW) treatment under salt-affected conditions. The rate of biodegradation of organic wastes was modeled using the first-order kinetics while the effect of salt concentrations was accounted by growth inhibition. Experimental data were used to determine model constants of the mathematical model. The experimental units were planted with cattail (Typha angustifolia) and fed with spiked municipal wastewater. The hydraulic retention time varied from 12 to 120 h and wastewater conductivity was in the range of 4–32 mS/cm. At specified conditions the model was found to well describe the trend of the experimental data in terms of BOD removal with the Pearson correlation of 0.872. The model also permits construction of a nomograph which can be used to aid the design and prediction of CW treatment under salt-affected conditions.