Improved solute transport and pollutant degradation model of free water surface constructed wetlands considering significant linear correlation between model parameters.

To unify the structures of solute transport and pollutant degradation models and evaluate the wetland performance conveniently, a pollutant degradation model combining first-order kinetics with the hybrid solute transport model (plug flow with dispersion + continuous stirred-tank reactor, PFD + CSTR) was developed. Orthogonal tests revealed significant correlation between the model parameters, and the original models were optimized via linear substitution of parameters. The improved PFD + CSTR solute transport model exhibited a satisfactory fit with the original model, and the average relative errors of the determination coefficient (R) and correlation coefficient were <5%.

[Effect of water depths on hydraulic performance of pond wetlands].

Pond wetlands have been widely used in the treatment of drainage water from paddy fields. However, wetland hydraulic performance and purification effects are affected by many factors, such as water depth, flow rate, aspect ratio and vegetation distribution, and the better understanding of these factors would be helpful to improve the quality of wetland design, operation and management. This paper analyzed the effect of three different water depths (20, 40 and 60 cm) on the hydraulic performance of pond wetland through the dye tracer experiments with Rhodamine WT.