Clarifying the correlations between hydraulic indicators evaluating the hydraulic performance of free water surface constructed wetlands.

Previous studies have shown a strong linear correlation between the common hydraulic indicators of free water surface constructed wetlands (FWS CWs), which results in the waste of computing resources and confusion in evaluating the hydraulic performance of FWS CWs. There is an urgent need to define a relatively independent and authoritative hydraulic indicator. In this study, based on three years' data, the correlations among five representative hydraulic indicators, that is, short-circuit index (φ), Morrill dispersion index (MDI), effective volume ratio (e), moment index (MI), and hydraulic efficiency (λ), were analyzed by combining a variety of methods.

Storages and leaching losses of soil water dissolved CO and NO on typical land use hillslopes in southeastern hilly area of China.

The dynamics of soil water dissolved CO and NO are important in determining the fates of soil CO and NO. However, related mechanisms and processes have been rarely revealed. In this study, storages and leaching losses of soil water dissolved CO and NO were investigated on the tea garden (TG) and bamboo forest (BF) hillslopes.

Quantitative prediction of the hydraulic performance of free water surface constructed wetlands by integrating numerical simulation and machine learning.

Quantitative prediction of the design parameter-influenced hydraulic performance is significant for optimizing free water surface constructed wetlands (FWS CWs) to reduce point and non-point source pollution and improve land utilization. However, owing to limitations of the test conditions and data scale, a quantitative prediction model of the hydraulic performance under multiple design parameters has not yet been established. In this study, we integrated field test data, mechanism model, statistical regression, and machine learning (ML) to construct such quantitative prediction models.

Machine learning exhibited excellent advantages in the performance simulation and prediction of free water surface constructed wetlands.

Optimizing the design and operation parameters of free water surface constructed wetlands (FWS CWs) in runoff regulation and wastewater treatment is necessary to improve the comprehensive performance. In this study, nine machine learning (ML) algorithms were successfully developed to optimize the parameter combinations for FWS CWs. The scale effect of surface area on wetland performance was determined based on consistently smaller predictions (-6.

Utilizing artificial neural network to simulate and predict the hydraulic performance of free water surface constructed wetlands.

Optimizing the hydraulic performance of free water surface constructed wetlands (FWS CWs) is of great economic and ecological value. However, there is a complex nonlinear relationship between the hydraulic performance and design parameters of FWS CWs. In this study, an artificial neural network (ANN) was applied to simulate and predict the hydraulic performance corresponding to different combinations of design parameters, and orthogonal design L (3) was used to determine the optimal combination of the important hyperparameters of the ANN.

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%.

Correction to: Response of solute transport model parameters to the combination of multiple design parameters and their quantitative expression with hydraulic indicators of FWS-constructed wetlands.

The correct Fig. 6 is presented in this paper.

Response of solute transport model parameters to the combination of multiple design parameters and their quantitative expression with hydraulic indicators of FWS-constructed wetlands.

Solute transport models and hydraulic indicators are commonly used to assess the flow pattern of free water surface-constructed wetlands (FWS CWs). However, the relationship between solute transport models and hydraulic performance remains poorly understood. The hybrid model comprised of plug flow with dispersion and continuous stirred tank reactors (PFD + CSTRs) was applied in this study.

Improved test to determine design parameters for optimization of free surface flow constructed wetlands.

Orthogonal tests were performed to assess the effect of design parameters on hydraulic and treatment performances of constructed wetlands. The results showed that water depth, layout of in- and outlet, flow rate, and aspect ratio mainly affected hydraulic performance, and water depth, plant spacing, and layout of in- and outlet mainly affected treatment performance. Optimal integrated performance was achieved with combination of 20-30 cm water depth, five evenly distributed inlets and one middle outlet, a flow rate of 0.

Test study of the optimal design for hydraulic performance and treatment performance of free water surface flow constructed wetland.

Orthogonal tests with mixed levels of design parameters of a free water surface flow constructed wetland were performed to assess their effect on hydraulic and treatment performance, and discover the relationship between the design parameters and the two performances. The results showed that water depth, plant spacing, and layout of in- and outlet mainly affected the two performances. Under 40cm depth, central pass of in- and outlet, 1.

[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.